Fellow WH-1000XM5 user here, I was able to get it working just by removing the manual hardware.pulseaudio configuration and just completely switching to pipewire, using the default settings:
services.pipewire = {
enable = true;
pulse.enable = true;
alsa.enable = true;
jack.enable = true;
};
# no manual sound or hardware.pulseaudio configuration needed
hardware.bluetooth = {
enable = true;
};
I am also using Plasma 5, but I am on NixOS unstable, so you might want to try updating if it doesn’t work. Btw, afaik 23.05 is currently deprecated anyway (23.11 is the current stable release).
A2DP seems to be working:
