I had problems with Chrome GPU rendering, which started lagging after a few minutes of browsing, until it became unusable, when used with the Hardware Acceleration option - ON.
As Opera is based on Chromium as well, it suffers from some GPU rendering problems, which caused the defective rendering in the Bookmarks menu, and when opening some extensions' menu (like adblock).
The solution is to launch Opera (or Chrome), with the following command, which disables the problematic DRI3, and reverts to the old one:
LIBGL_DRI3_DISABLE=1 opera --ignore-gpu-blacklist
Hope I saved someone a few days of Trichotillomania 