XnView Software

This has already worked in versions of XnViewMP/OpenSuse Tubleweed before summer, broke for about 2 months, maybe three now. Acutally running 1.5.5. Overall, XnViewMP runs great here on OpenSuse/KDE/Wayland (using the tar).
But when I press F11 for fullscreen, my screen turns black, clicks a few times as if it would change resolution/frequency. Then The image is shown, but about the upper third of the screen is black, then the upper part of the image is shown and the lower part of the image is missing. And this is the same effect, every time I skip to the next image.
As Tumbleweed is a rolling distro and I dont use XnViewMP fullscreen every day, I cannot tell if that came with an OS or application update.

and you have not this issue with previous version?

No, this worked a few months ago with a previous version, but that has also been an older version of my distro.
Can I download older versions of XnViewMP? I could double check with a version from, say, May or June.

Earlier versions.

OK, double checked with 1.4.5, same problem, got worse now.
Whenever I browse a directory with videos and open a video, XnViewMP crashes under Wayland. Nothing fancy, just some videos I took with my smartphone camera. Under X11, everything works fine.