Seems to affect my system as well. I am on Kubuntu 21.04 with KDE Plasma 5.22.2. Thunderbird is basically unusable on Wayland for me. The whole ui is flickering especially when a reminder notification appears. Thunderbird is the only application that is behaving like that. Firefox runs without problems. I have also noticed graphical artifacts in GIMP when running the Plasma Wayland Session.
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to thunderbird in Ubuntu. https://bugs.launchpad.net/bugs/1932328 Title: Thunderbird under Wayland does not correctly close (or manage) windows Status in thunderbird package in Ubuntu: Confirmed Bug description: Using Ubuntu 21.04 (Hirsute) that starts in Wayland, by default. Thunderbird version: 78.11.0 with "gnome-support" package. Same problem in safe mode. Description: By default in this context, TB is a Wayland task. When opening a compose windows (or reply or transfer), sending mail apparently close the windows, but gnome shell continue to show multiple "points", as if multiple windows are still active. And after closing TB, it seems maintained in the same state, so it becomes impossible to relaunch it from the desk. But task manager of "looking glass" do not show it and it is possible to launch from terminal. Provisional solution: Modify .desktop file to launch with --display=:0 option, that force to use XWayland interface, as shown by xlsclients (for example). But it is actually a bug under Wayland context, that also badly interfer with many add-ons or extensions. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/1932328/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp