Weird visual glitch in Firefox when using split screen

[Rence_k]

Hi,

I'm seeing a strange visual issue in Firefox.

When using split-screen mode in Windows 11, I sometimes see grid-like patterns over the content when scrolling. It lasts a few seconds and then returns to normal.

This ONLY happens when Firefox is in split-screen mode (on either side of the split). I haven't noticed it in full-screen mode.

I already tried disabling hardware acceleration, but the issue still occurs.

This started recently after months of normal use.

Has anyone else experienced this, or does anyone know what could cause it?

Thanks.

[Rence_k]

I forgot to mention that this only occurs after several hours of working in split-screen mode. A transparent grid-like pattern briefly appears while scrolling, then disappears shortly afterward. Restarting Firefox makes the issue go away, but it eventually comes back after several more hours of use.