Bug 422254

After the upgrade from Kwin 5.18.5 to 5.19 Beta OpenGL and Vulkan several applications show an empty window/frame. I've noticed this when trying some games that worked perfectly fine on Plasma Wayland before the upgrade. The issue is visible already when I open glxgears and vkcube, then I get only a XWayland window without any content. This worked fine in Plasma 5.18 and older! Upgrading to Mesa-git didn't change anything. When downgrading to Plasma 5.18 all applications work fine again.
If I manually resize the glxgears or vkcube window on Plasma 5.19 beta, the content is visible afterwards. Some fullscreen games will show a lot of flickering on screen, manually setting it to window mode and then fullscreen (ALT-F3) will show the content as well. But these are just some bad workarounds.


STEPS TO REPRODUCE
1. Start on glxgears and vkcube on Plasma Wayland

OBSERVED RESULT
- Empty window, frame is visible, but no content

EXPECTED RESULT
- Content is visible

Operating System: Arch Linux 
KDE Plasma Version: 5.18.90
KDE Frameworks Version: 5.70.0
Qt Version: 5.15.0
Kernel Version: 5.6.15-arch1-1
OS Type: 64-bit
Processors: 24 × AMD Ryzen 9 3900X 12-Core Processor
Memory: 31,4 GiB Arbeitsspeicher
Graphics Processor: AMD Radeon VII