A clean install of 21.04 (erase disc) & then running software update causes some terrible window management problems.

When attempting to send an Email with thunderbird (clicking send button), the "Write" window becomes a ghost object, (unmanaged window) - so thunderbird thinks its still there in the windows list & in the dock, but it doesn't exist.
If you quit thunderbird, the ghost window remains as 1 dot in the dock & thunderbird cant be relaunched. If you quit thunderbird by the app menu instead, the session will crash & you are logged out.
This also start to happen with nautilus windows & then you cant open or use nautilus at all.

Ive run this clean install 3 times now & every time its the same, as soon as i run the OS update, window management flips out.
As I say, its just install os, don't change anything, run the update - boom!

journal shows the following errors when trying to click on thunderbird in the dock or in the apps manager

gnome-shell[1000]: Trying to activate unmanaged window 'W5'

gnome-shell[1000]: Couldn't find child [0x559e8aecad50 Gjs_ui_windowPreview:first-child last-child ("rico@Sulaco: ~")] in window slots