kwin_x11 fails to render Firefox in specific scenario

Greetings fellow SUSE users.

I have been having an issue where I thought my specific setup was just not configured properly and that a fresh distro install on a new drive would fix it. Apparently I was incorrect.

I have made a post to reddit which also features a video of the problem in action. The window fails to update unless forced to be redrawn, such as resizing. However, the browser still behaves as it should under the hood, as you can blindly click links and the browser will navigate to them (only viewable after a forced redraw event).

In most instances, this can be fixed with a

kwin_x11 --replace &

command in the terminal, but it’s become very cumbersome and annoying and does not solve the root issue.

The specific conditions in which I usually can reproduce this behavior is scrolling my twitter likes. Twitter timelines typically stop after so many tweets are rendered, but the “likes” tab can be scrolled indefinitely. After scrolling a LOT of tweets, the memory usage does go up. But what specifically causes kwin to fail to update Firefox’s render space is a mystery to me.

Another way to recover is to turn compositor off and on. Set a shortcut for that. Or, consider always running with compositor off. I’ve noticed a similar behavior myself a couple months ago, in particular running a few days without reboot (plasma/xorg/nvidia). Haven’t noticed anymore although I believe the problem still there (switched to iGPU though).

Exactly the same plasma/xorg/nvidia. Huh. It’s such a bizarre issue. I’ve disabled the compositor and will reboot on the next error to see how drastic of a difference it will make my overall daily driver experience.

Disabling the compositor did not fix the issue :frowning:

I suggest you report it to KDE bugzilla, in particular you have a repro which should be helpful.

There are a few closed reports, you might need to open a new one: