Created attachment 151298 [details]
one crash report, the others look similar, and a kscreen file

SUMMARY
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I recently changed my display configuration, one DP and one HDMI, when I disable the HDMI one it works fine for around 10 seconds, then applications start crashing (see kcrash and kscreen files in the attachment).
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STEPS TO REPRODUCE
0. Probably some config files somewhere
1. Disable HDMI monitor in the System Settings
2. Wait for a few seconds
3. Krash
Optionally if I reenable it, everything continues to work as expected

OBSERVED RESULT
the HDMI display turns off, but crashes kde programs

EXPECTED RESULT
don't crash kde programs

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Archlinux 5.18.16-zen
KDE Plasma Version: 5.25.4
KDE Frameworks Version: 5.96.0
Qt Version: 5.15.5

ADDITIONAL INFORMATION

If I disable the DP (Acer) monitor nothing strange happens. Also, the HDMI (AOC) monitor was the original. There was another DP (ASUS) monitor, in the place of my new one, with the the same HDMI (AOC) monitor. In the past I used the AOC monitor's DP, and the ASUS's HDMI, but after an accident I had to switch them.
The monitors are connected to a RX 6600, but there is also a GTX 750 Ti in the system.
I haven't found such issues in X.