XnView Software

XnViewMP 1.6.1 64bit
Windows11 (22H2), display resolution 3840x2160, win scaling 150%

Viewer - fullscreen
blinking black under certain conditions

To reproduce:
1. open any video/image in Fullscreen mode
2. try any of the following actions:
- press F12
- press Del button
- click LMB, move mouse a little bit, click RMB, repeat few times
image will blink (turn black for a moment)

if there is no blinking with image file - open video file, reproduce issue, scroll to image file, issue will appear

ps. same issue in 1.4.5, 1.5.5, no issue in 1.0.0

with only image file, are you able to reproduce?

no,
looks like it only happens if video files has been opened in fullscreen previously

i'm not able to reproduce