SUMMARY
***
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***

After upgrading my Arch system from plasma 5.27.8-2 to 6.0.1 i am experiencing the problem.
Setup exactly the same as before, so likely the upgrade is the cause.
nothing gets logged in syslog, please advise how to debug this so i can provide more information

STEPS TO REPRODUCE
1. lock screen or wait for timer to lock screen

OBSERVED RESULT
1. screen flickers and for  ~ 1 second content is shown then flickers then content etc
also keyboard backlight goes on and off when screen content is displayed
2. i can enter my password and unlock while it flickers.
after that flickering continues on desktop too.
3. passing some time hitting keys and using the mouse desktop comes back and i can use normal.
EXPECTED RESULT

Unlock system without flickering

SOFTWARE/OS VERSIONS

Operating System: Arch Linux 
KDE Plasma Version: 6.0.1
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2
Kernel Version: 6.7.8-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 4 × Intel® Core™ i7-6600U CPU @ 2.60GHz
Memory: 15.3 GiB of RAM
Graphics Processor: Mesa Intel® HD Graphics 520
Manufacturer: LENOVO
System Version: ThinkPad T570


ADDITIONAL INFORMATION

let me know how to get more debug info i can share here