Mail reading panel is flaky in Chrome on Linux (solved)

[dwasifark]

Sometimes, when I move my cursor around on the screen while Roundcube is open in Chrome with an email displaying in the reading panel, the contents of the panel disappear, or mostly disappear, and then sometimes (not always) reappear.  This occasionally happens to the Roundcube buttons as well. 

This has persisted through a Roundcube version upgrade, and a couple of Chrome updates, as well as completely removing and reinstalling Chrome from scratch.  It does not seem to be related to any plugin, but it's hard to say that with 100% certainty as the problem is intermittent.

Microsoft Edge for Linux is not affected, which is rather surprising given that it is a Chromium-based browser too.

I am using Chrome 118.0.5993.88 on Linux Mint Debian Edition with MATE desktop environment.

Anyone else seeing this issue?

[dwasifark]

The issue eventually started appearing on Edge for Linux too, and then I noticed both browsers getting flaky in the same way on other sites.

I traced it to a video driver problem that just happened to manifest first when using Roundcube.  Switching from the open source nouveau driver to the proprietary Nvidia driver made all the issues go away.