My configuration is in this topic, plus the Wayland stuff from this topic.
Normal login to a Wayland session works.
Journal output below. How can I solve this issue?
Summary
dec 04 13:01:11 nixos sddm[1311]: Setting default cursor
dec 04 13:01:11 nixos sddm[1311]: Could not setup default cursor
dec 04 13:01:11 nixos sddm[1311]: Running display setup script "/nix/store/bg62x4kzkq8rrayrby41w75j3xkiqvck-Xsetup"
dec 04 13:01:11 nixos sddm[1311]: Display server started.
dec 04 13:01:11 nixos sddm[1311]: Reading from "/nix/store/r1wws2a31sy2h3xbqvxlw3nl1psng40i-desktops/share/wayland-sessions/plasmawayland.desktop"
dec 04 13:01:11 nixos sddm[1311]: Reading from "/nix/store/r1wws2a31sy2h3xbqvxlw3nl1psng40i-desktops/share/wayland-sessions/plasmawayland.desktop"
dec 04 13:01:11 nixos sddm[1311]: Session "/nix/store/r1wws2a31sy2h3xbqvxlw3nl1psng40i-desktops/share/wayland-sessions/plasmawayland.desktop" selected, command: "/nix/store/dmfkma5jx3hxndp4dypys3nzqq11szpb-plasma-workspace-5.23.3/libexec/plasma-dbus-run-session-if-needed /nix/store/dmfkma5jx3hxndp4dypys3nzqq11szpb-plasma-workspace-5.23.3/bin/startplasma-wayland"
dec 04 13:01:11 nixos sddm-helper[1349]: [PAM] Starting...
dec 04 13:01:11 nixos sddm-helper[1349]: [PAM] Authenticating...
dec 04 13:01:11 nixos sddm-helper[1349]: [PAM] returning.
dec 04 13:01:11 nixos sddm[1311]: Authenticated successfully
dec 04 13:01:11 nixos sddm-helper[1349]: pam_unix(sddm-autologin:session): session opened for user user2(uid=1001) by (uid=0)
dec 04 13:01:11 nixos systemd[1]: Created slice Slice /user/1001.
dec 04 13:01:11 nixos systemd[1]: Starting User Runtime Directory /run/user/1001...
dec 04 13:01:11 nixos systemd-logind[963]: New session 1 of user user2.
dec 04 13:01:11 nixos systemd[1]: Finished User Runtime Directory /run/user/1001.
dec 04 13:01:11 nixos systemd[1]: Starting User Manager for UID 1001...
dec 04 13:01:11 nixos systemd[1351]: pam_unix(systemd-user:session): session opened for user user2(uid=1001) by (uid=0)
dec 04 13:01:11 nixos systemd[1351]: Queued start job for default target Main User Target.
dec 04 13:01:11 nixos systemd[1351]: Created slice User Application Slice.
dec 04 13:01:11 nixos systemd[1351]: Reached target Paths.
dec 04 13:01:11 nixos systemd[1351]: Reached target Timers.
dec 04 13:01:11 nixos systemd[1351]: Starting D-Bus User Message Bus Socket...
dec 04 13:01:11 nixos systemd[1351]: Listening on PipeWire PulseAudio.
dec 04 13:01:11 nixos systemd[1351]: Listening on Multimedia System.
dec 04 13:01:11 nixos systemd[1351]: Listening on D-Bus User Message Bus Socket.
dec 04 13:01:11 nixos systemd[1351]: Reached target Sockets.
dec 04 13:01:11 nixos systemd[1351]: Reached target Basic System.
dec 04 13:01:11 nixos systemd[1]: Started User Manager for UID 1001.
dec 04 13:01:11 nixos systemd[1351]: Starting Run user-specific NixOS activation...
dec 04 13:01:11 nixos systemd[1351]: Starting Run KDE Plasma via systemd...
dec 04 13:01:11 nixos systemd[1]: Started Session 1 of User user2.
dec 04 13:01:11 nixos nixos-activation-start[1360]: removed '/home/user2/.cache/icon-cache.kcache'
dec 04 13:01:11 nixos sddm-helper[1349]: pam_kwallet5(sddm-autologin:session): pam_kwallet5: pam_sm_open_session
dec 04 13:01:11 nixos sddm-helper[1349]: Starting: "/nix/store/8xylb1max36qx67s7f8d9ckmpw392z7a-sddm-0.19.0/share/sddm/scripts/wayland-session /nix/store/dmfkma5jx3hxndp4dypys3nzqq11szpb-plasma-workspace-5.23.3/libexec/plasma-dbus-run-session-if-needed /nix/store/dmfkma5jx3hxndp4dypys3nzqq11szpb-plasma-workspace-5.23.3/bin/startplasma-wayland"
dec 04 13:01:11 nixos sddm-helper[1349]: pam_kwallet5(sddm-autologin:session): pam_kwallet5: open_session called without kwallet5_key
dec 04 13:01:11 nixos sddm-helper[1363]: Jumping to VT 1
dec 04 13:01:11 nixos sddm-helper[1363]: VT mode didn't need to be fixed
dec 04 13:01:11 nixos xserver-wrapper[1314]: (II) event4 - Power Button: device removed
dec 04 13:01:11 nixos nixos-activation-start[1365]: removed '/home/user2/.cache/ksycoca5_fi_ANbHMbB_ipUvBQH9GvBKM3ZpB4Q='
dec 04 13:01:11 nixos nixos-activation-start[1365]: removed '/home/user2/.cache/ksycoca5_fi_pcN3vGrJ2nSQLzoAfbTZ89+zvzc='
dec 04 13:01:11 nixos nixos-activation-start[1365]: removed '/home/user2/.cache/ksycoca5_fi_PplYXDWa2aWH60pmTylIOipxDMo='
dec 04 13:01:11 nixos nixos-activation-start[1365]: removed '/home/user2/.cache/ksycoca5_fi_U+dYY5uzaI9fM2VA6U25kNPxWZw='
dec 04 13:01:11 nixos nixos-activation-start[1365]: removed '/home/user2/.cache/ksycoca5_fi_xzcCl1+ow5KKRvImLR8qP6vP+qs='
dec 04 13:01:11 nixos systemd[1351]: Finished Run KDE Plasma via systemd.
dec 04 13:01:11 nixos xserver-wrapper[1314]: (II) event5 - Video Bus: device removed
dec 04 13:01:11 nixos nixos-activation-start[1366]: kbuildsycoca5 running...
dec 04 13:01:11 nixos xserver-wrapper[1314]: (II) event1 - Power Button: device removed
dec 04 13:01:11 nixos xserver-wrapper[1314]: (II) event2 - Sleep Button: device removed
dec 04 13:01:12 nixos xserver-wrapper[1314]: (II) event7 - HD Webcam: HD Webcam: device removed
dec 04 13:01:12 nixos xserver-wrapper[1314]: (II) event8 - HD Webcam: IR Camera: device removed
dec 04 13:01:12 nixos xserver-wrapper[1314]: (II) event11 - USB Keyboard: device removed
dec 04 13:01:12 nixos xserver-wrapper[1314]: (II) event15 - USB Keyboard System Control: device removed
dec 04 13:01:12 nixos xserver-wrapper[1314]: (II) event16 - USB Keyboard Consumer Control: device removed
dec 04 13:01:12 nixos xserver-wrapper[1314]: (II) event17 - USB Keyboard Mouse: device removed
dec 04 13:01:12 nixos xserver-wrapper[1314]: (II) event18 - USB Keyboard: device removed
dec 04 13:01:12 nixos xserver-wrapper[1314]: (II) event9 - UNIW0001:00 093A:0255 Mouse: device removed
dec 04 13:01:12 nixos xserver-wrapper[1314]: (II) event10 - UNIW0001:00 093A:0255 Touchpad: device removed
dec 04 13:01:12 nixos xserver-wrapper[1314]: (II) event0 - AT Translated Set 2 keyboard: device removed
dec 04 13:01:12 nixos xserver-wrapper[1314]: (II) AIGLX: Suspending AIGLX clients for VT switch
dec 04 13:01:12 nixos sddm[1311]: Session started
dec 04 13:01:12 nixos systemd[1]: systemd-rfkill.service: Deactivated successfully.
dec 04 13:01:12 nixos dbus-daemon[913]: [system] Activating via systemd: service name='org.freedesktop.locale1' unit='dbus-org.freedesktop.locale1.service' requested by ':1.16' (uid=1001 pid=1363 comm="/nix/store/dmfkma5jx3hxndp4dypys3nzqq11szpb-plasma" label="kernel")
dec 04 13:01:12 nixos systemd[1]: Starting Locale Service...
dec 04 13:01:12 nixos dbus-daemon[913]: [system] Successfully activated service 'org.freedesktop.locale1'
dec 04 13:01:12 nixos systemd[1]: Started Locale Service.
dec 04 13:01:12 nixos systemd[1351]: Started D-Bus User Message Bus.
dec 04 13:01:12 nixos systemd[1351]: Finished Run user-specific NixOS activation.
dec 04 13:01:12 nixos systemd[1351]: Reached target Main User Target.
dec 04 13:01:12 nixos systemd[1351]: Startup finished in 562ms.
dec 04 13:01:13 nixos wpa_supplicant[1219]: wlp1s0: CTRL-EVENT-REGDOM-CHANGE init=DRIVER type=COUNTRY alpha2=DE
dec 04 13:01:13 nixos dhcpcd[888]: wlp1s0: new hardware address: c8:b2:9b:a3:95:58
dec 04 13:01:13 nixos NetworkManager[1104]: <warn> [1638615673.5447] device (wlp1s0): no secrets: No agents were available for this request.
dec 04 13:01:13 nixos NetworkManager[1104]: <warn> [1638615673.5454] device (wlp1s0): Activation: failed for connection 'TP-Link_1A62'
dec 04 13:01:13 nixos dhcpcd[888]: wlp1s0: new hardware address: 02:2d:ae:6b:bd:d4
dec 04 13:01:14 nixos dbus-daemon[1369]: [session uid=1001 pid=1369] Activating service name='org.kde.KSplash' requested by ':1.3' (uid=1001 pid=1441 comm="/nix/store/dmfkma5jx3hxndp4dypys3nzqq11szpb-plasma" label="kernel")
dec 04 13:01:14 nixos systemd[1351]: Created slice User Background Tasks Slice.
dec 04 13:01:14 nixos systemd[1351]: Created slice User Core Session Slice.
dec 04 13:01:14 nixos systemd[1351]: Starting Baloo File Indexer Daemon...
dec 04 13:01:14 nixos systemd[1351]: Starting Early Plasma setup...
dec 04 13:01:14 nixos systemd[1448]: kde-baloo.service: Failed to locate executable /nix/store/hi00pi4pssm9896ssi1y65jc2bwdy21x-baloo-5.87.0/bin/kde-systemd-start-condition: No such file or directory
dec 04 13:01:14 nixos systemd[1448]: kde-baloo.service: Failed at step EXEC spawning /nix/store/hi00pi4pssm9896ssi1y65jc2bwdy21x-baloo-5.87.0/bin/kde-systemd-start-condition: No such file or directory
dec 04 13:01:14 nixos systemd[1351]: Starting KDE Config Module Initialization...
dec 04 13:01:14 nixos systemd[1351]: Starting KDE Session Management Server...
dec 04 13:01:14 nixos systemd[1351]: Started Unlock kwallet from pam credentials.
dec 04 13:01:14 nixos systemd[1351]: Starting KDE Daemon...
dec 04 13:01:14 nixos systemd[1351]: kde-baloo.service: Skipped due to 'exec-condition'.
dec 04 13:01:14 nixos systemd[1351]: Condition check resulted in Baloo File Indexer Daemon being skipped.
dec 04 13:01:14 nixos plasma-early-setup-start[1454]: removed '/home/user2/.cache/icon-cache.kcache'
dec 04 13:01:14 nixos plasma-early-setup-start[1458]: removed '/home/user2/.cache/ksycoca5_fi_MvFS_oE9Ayg0iCJRoKQcIbVfgdU=.lock'
dec 04 13:01:14 nixos plasma-early-setup-start[1458]: removed '/home/user2/.cache/ksycoca5_fi_P8127WmS9XlQNe3lnPCMPoFpLxU='
dec 04 13:01:14 nixos plasma-early-setup-start[1459]: kbuildsycoca5 running...
dec 04 13:01:14 nixos ksmserver[1451]: Qt: Session management error: networkIdsList argument is NULL
dec 04 13:01:14 nixos systemd[1351]: Started KDE Session Management Server.
dec 04 13:01:15 nixos systemd[1351]: Started KDE Daemon.
dec 04 13:01:15 nixos dbus-daemon[1369]: [session uid=1001 pid=1369] Successfully activated service 'org.kde.KSplash'
dec 04 13:01:15 nixos sddm-helper[1349]: [PAM] Closing session
dec 04 13:01:15 nixos sddm-helper[1349]: pam_unix(sddm-autologin:session): session closed for user user2
dec 04 13:01:15 nixos ksmserver[1451]: The X11 connection broke (error 1). Did the X11 server die?
dec 04 13:01:15 nixos sddm-helper[1349]: pam_kwallet5(sddm-autologin:session): pam_kwallet5: pam_sm_close_session
dec 04 13:01:15 nixos sddm-helper[1349]: [PAM] Ended.
dec 04 13:01:15 nixos systemd[1351]: Finished Early Plasma setup.
dec 04 13:01:15 nixos systemd[1351]: Reached target Session services which should run early before the graphical session is brought up.
dec 04 13:01:15 nixos sddm[1311]: Auth: sddm-helper exited with 1
dec 04 13:01:15 nixos systemd-logind[963]: Session 1 logged out. Waiting for processes to exit.
dec 04 13:01:15 nixos systemd[1351]: plasma-ksmserver.service: Main process exited, code=exited, status=1/FAILURE
dec 04 13:01:15 nixos systemd[1351]: plasma-ksmserver.service: Failed with result 'exit-code'.
dec 04 13:01:15 nixos kcminit_startup[1460]: Initializing "kcm_mouse" : "kcminit_mouse"
dec 04 13:01:15 nixos kcminit_startup[1460]: Initializing "kcm_style" : "kcminit_style"
dec 04 13:01:16 nixos kded5[1453]: Installing the delayed initialization callback.
dec 04 13:01:16 nixos dhcpcd[888]: wlp1s0: new hardware address: c8:b2:9b:a3:95:58
dec 04 13:01:16 nixos wpa_supplicant[1219]: wlp1s0: WPS-PBC-ACTIVE
dec 04 13:01:17 nixos systemd[1]: NetworkManager-dispatcher.service: Deactivated successfully.
dec 04 13:01:20 nixos dbus-daemon[913]: [system] Activating via systemd: service name='org.freedesktop.nm_dispatcher' unit='dbus-org.freedesktop.nm-dispatcher.service' requested by ':1.8' (uid=0 pid=1104 comm="/nix/store/dvy92srs8c9ba55f19cq87mypflmrpa1-networ" label="kernel")
dec 04 13:01:20 nixos kcminit_startup[1510]: /run/current-system/sw/bin/xrdb: Connection reset by peer
dec 04 13:01:20 nixos kcminit_startup[1510]: /run/current-system/sw/bin/xrdb: Can't open display ':1'
dec 04 13:01:20 nixos kcminit_startup[1460]: The Wayland connection broke. Did the Wayland compositor die?
dec 04 13:01:20 nixos systemd[1351]: Started KDE Config Module Initialization.
dec 04 13:01:20 nixos systemd[1351]: Starting KDE Configuration Module Initialization (Phase 1)...
dec 04 13:01:20 nixos systemd[1351]: Starting KDE Plasma Workspace...
dec 04 13:01:20 nixos qdbus[1528]: Service 'org.kde.kcminit' does not exist.
dec 04 13:01:20 nixos systemd[1351]: plasma-kcminit-phase1.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
dec 04 13:01:20 nixos systemd[1351]: plasma-kcminit-phase1.service: Failed with result 'exit-code'.
dec 04 13:01:20 nixos systemd[1351]: Failed to start KDE Configuration Module Initialization (Phase 1).
dec 04 13:01:20 nixos kded5[1453]: bluedevil: Created
dec 04 13:01:20 nixos .kded5-wrapped[1453]: failed to commit changes to dconf: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name ca.desrt.dconf was not provided by any .service files
dec 04 13:01:20 nixos plasmashell[1529]: Failed to create wl_display (Connection refused)
dec 04 13:01:20 nixos plasmashell[1529]: qt.qpa.plugin: Could not load the Qt platform plugin "wayland" in "" even though it was found.
dec 04 13:01:20 nixos plasmashell[1529]: This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
dec 04 13:01:20 nixos plasmashell[1529]: Available platform plugins are: wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.
dec 04 13:01:20 nixos .kded5-wrapped[1453]: failed to commit changes to dconf: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name ca.desrt.dconf was not provided by any .service files
dec 04 13:01:20 nixos .kded5-wrapped[1453]: failed to commit changes to dconf: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name ca.desrt.dconf was not provided by any .service files
dec 04 13:01:20 nixos .kded5-wrapped[1453]: failed to commit changes to dconf: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name ca.desrt.dconf was not provided by any .service files
dec 04 13:01:20 nixos .kded5-wrapped[1453]: failed to commit changes to dconf: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name ca.desrt.dconf was not provided by any .service files
dec 04 13:01:20 nixos systemd[1]: Finished Network Manager Wait Online.
dec 04 13:01:20 nixos systemd[1]: session-1.scope: Deactivated successfully.
dec 04 13:01:20 nixos systemd[1]: session-1.scope: Consumed 2.810s CPU time, no IP traffic.
dec 04 13:01:20 nixos systemd[1]: Created slice Slice /system/systemd-coredump.
dec 04 13:01:20 nixos systemd[1]: Starting Network Manager Script Dispatcher Service...
dec 04 13:01:20 nixos systemd[1]: Started Process Core Dump (PID 1535/UID 0).
dec 04 13:01:20 nixos systemd-logind[963]: Removed session 1.
dec 04 13:01:20 nixos dbus-daemon[913]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher'
dec 04 13:01:20 nixos systemd[1]: Started Network Manager Script Dispatcher Service.
dec 04 13:01:20 nixos NetworkManager[1104]: <warn> [1638615680.6659] device (wlp1s0): Deactivation failed: GDBus.Error:fi.w1.wpa_supplicant1.NotConnected: This interface is not connected
dec 04 13:01:20 nixos dhcpcd[888]: wlp1s0: new hardware address: 62:e6:64:64:0c:80
dec 04 13:01:20 nixos .kded5-wrapped[1453]: failed to commit changes to dconf: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name ca.desrt.dconf was not provided by any .service files
dec 04 13:01:20 nixos .kded5-wrapped[1453]: failed to commit changes to dconf: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name ca.desrt.dconf was not provided by any .service files
dec 04 13:01:20 nixos systemd-coredump[1544]: Process 1529 (.plasmashell-wr) of user 1001 dumped core.
dec 04 13:01:20 nixos systemd[1]: systemd-coredump@0-1535-0.service: Deactivated successfully.
dec 04 13:01:20 nixos systemd[1351]: plasma-plasmashell.service: Main process exited, code=dumped, status=6/ABRT
dec 04 13:01:20 nixos systemd[1351]: plasma-plasmashell.service: Failed with result 'core-dump'.
dec 04 13:01:20 nixos systemd[1351]: Failed to start KDE Plasma Workspace.
dec 04 13:01:20 nixos systemd[1351]: plasma-core.target: Bound to unit plasma-ksmserver.service, but unit isn't active.
dec 04 13:01:20 nixos systemd[1351]: Dependency failed for KDE Plasma Workspace Core.
dec 04 13:01:20 nixos systemd[1351]: Dependency failed for KDE Plasma Workspace.
dec 04 13:01:20 nixos systemd[1351]: plasma-workspace@wayland.target: Job plasma-workspace@wayland.target/start failed with result 'dependency'.
dec 04 13:01:20 nixos systemd[1351]: plasma-core.target: Job plasma-core.target/start failed with result 'dependency'.