[qubes-users] [Qubes 4.1] issue with thunderbird after recent debian update

Hi,

since a recent update, thunderbird throws artefacts on xfce screen
(parts of its menu), that spawn virtual screen, survive log off & on
again, but disappear if VM is closed. And re-appear when thunderbird is
restarted. Very annoying! Am I alone with this type of glitch?

Thanks, best, Bernhard