Comment 0 for bug 1932328

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.