GNOME Music doesn't show m4a files

I’m using NixOS-24-05 with the GNOME desktop. The GNOME Music player (gnome-music) doesn’t show m4a files in my $HOME/Music directory. To see audio properties in Files I added

  environment.sessionVariables.GST_PLUGIN_SYSTEM_PATH_1_0 = lib.makeSearchPathOutput "lib" "lib/gstreamer-1.0" (with pkgs.gst_all_1; [

Is some extra configuration required?

Other applications like VLC and mpv have no problems playing the files.

Are new files in other formats detected? Might be tracker-miners: not indexing music files · Issue #319587 · NixOS/nixpkgs · GitHub.

Actually, no audio file is detected. I thought that it was just m4a because I recently added some mp3 without issues, while the m4a that I added today were not detected. However, in the mean time I upgraded my system.