Recently, I have a lot of situations where kwin_x11 stops. The desktop freezes, though most often I can start a new instance, and kill the old ones.

In some cases, the desktop freezes completely, and my only solution so far is to log into a shell and kill startkde.

In some cases, a notifications pops up and tells me that the window effects have been restarted, because they were reset. Often the desktop will be unstable after that.

Problems appears most often when using non-kde apps like libreoffice, firefox.

Maximizing windows is often involved.

Gwenview causes problems, and the file dialog in dolphin.

Anyone else experiencing similar problems? For me, they have worsened with the last archlinux update.

Which graphics driver are you using? Does this occur if you export LIBGL_DRI3_DISABLE=1?

I use the intel i915 driver. Where should i export that variable, in ~/.bashrc or somewhere else?

bashrc should do, or a script file (executable and exporting the variable) in ~/.config/plasma-workspace/env/.

I put "export LIBGL_DRI3_DISABLE=1" in ~/.config/plasma-workspace/env/disabledri3.sh and restarted my kde session, but I just got at window effects restart again.