Hello friends of linux!

For a few days now, I have had a problem with the suspend function. When I click onto "Standby-Modus" (German GUI) in the menu, the screen turns black with the pointer still visible and the laptop is unresponsive to keyboard hits or mouse movement for a few seconds, then I get to the locked screen. This behaviour is the same when I enter systemctl suspend (also when using sudo) or when I close the lid.

Since I have read some forum posts about similar problems being related to GPUs, I should report as well that I have had some hickups with that respect:
1. Sometimes when I connect a second screen via HDMI, the desktop surface seems fine but any window that I drag there is flickering (some parts of the writing flickering up and down a bit). Using the VGA output and a converter to HDMI worked as a workaround.
2. Yesterday, after another try to use suspend, all my desktop symbols were gone. I don't remember how I brought them back (probably a restart or another attempt to suspend), but when they reappeared, they were all aligned at the top of the screen, not the way I had arranged them before.
This just as supplementary info in case this helps localising the problem.

Technical data:
Laptop: Lenovo T460
GPU: VGA compatible controller: Intel Corporation Skylake GT2 [HD Graphics 520] (rev 07)
OS: Kubuntu 22.04
Graphics platform: X11

I would be happy if anyone could help me with that. If I can provide additional helpful information, please tell me.

Best regards,
Svenja