I have had the same problem as Roland for a long time and today I finally decided to troubleshoot it.
Quickly came to the conclusion that notify-send was the culprit. Through trial and error I added this to my 400-notify-send script to get it working: export XDG_RUNTIME_DIR=$(sed -z -n s/^XDG_RUNTIME_DIR=//p "/proc/$NR_SESSPPID/environ") Then I found this bug and I tried Rolands solution and it also works for me. I have no idea which solution may be more appropriate or not. I run KDE and this is Debian Bullseye (currently Debian stable) but the 400-notify-script has not changed between the releases (except whitespace and comments). Regards Andreas
