Notifications don't show anymore (Debian/KDE)

[mYnDstrEAm]

On Debian12/KDE when I insert some USB device to one machine it shows the notifications just fine. I had configured a new autostart entry in KDE Autostarts that runs usbguard-notifier. On another machine where I did the same, they don't show even though usbguard-daemon and usbguard-notifier are running.

I tried quitting and then restarting both by running sudo systemctl start usbguard.service and usbguard-notifier &. However, notifications still don't show up. I learned the proper way to start usbguard-notifier is by running systemctl start --user usbguard-notifier.service so I quit the process and did that but it didn't help.

The only way to use the USB device is to use usbguard list-devices then usbguard allow-device id. Not related to this problem but are these allowances temporary because that would be best (for the duration that it's plugged in) and they don't show up in usbguard list-rules but it's not clear from the info displayed when running usbguard.

How to make the notifications show up again and prevent this problem from occurring?

[mYnDstrEAm]

They didn't show because I had a second display (it's turned off) disabled in the KDE display configuration. There are still some issues with additional display in Debian12. The notifications are showing again after disabling it.