DPMS disabled after upgrade to kubuntu 22.04

[Erik Rull]

Hi all,

I have no clue yet what went wrong, at least there was no error message during
the upgrade process from 20.04 LTS to 22.04 LTS kubuntu...

But - since this upgrade, the two screens of my system never switch off - I set
the screen power off to 10 minutes - nothing happens.
If I call the switchoff via xset manually, the screens go into standby immediately.
Works - but not really usable when locking the system and leaving the room.

And - if I set some settings in xset, I see the settings changing but they do
not work (eg. xset +dpms 30 30 30 and xset s 30 10 have no effect at all, but
they are shown in xset q)
And also interesting - when applying new power off times in the power management
dialog, then DPMS gets always disabled when calling xset q afterwards (before it
was enabled by me)
The system is still on X11, not on Wayland - why - I don't know - I thought that
ubuntu 22.04 based installations will default to Wayland...

Maybe something is mixed up between Wayland and X?

Thanks.

Best regards,

Erik