I am having the same issue.I tried fixing the issue by installing "glib:bin" manually, the error "gdbus" error message now goes away, but the program still shuts down quietly and does not lock the screen.
- bug#75288: gnu: xfce4-session: xflo... Ashvith Shetty
- bug#75288: gnu: xfce4-session:... Ricardo Prudon
- bug#75288: gnu: xfce4-session:... 宋文武 via Bug reports for GNU Guix
