SUMMARY
The screen flashes in some situations, it started with KDE5.22
100% reproducible for me.


STEPS TO REPRODUCE
1. Start new game
2. Overview screen is drawn (where you can select the type of game)
3. Screen flashes, perhaps the screen is drawn again
4 After you select a game and press OK, the overview screen flashes again
  before we go to the game itself. This works OK.

OBSERVED RESULT
see step 3.

EXPECTED RESULT
No flashes, like before

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: NEON, KDE 5.22
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION