Hello,
I also have this kind of situation and/or file recovery windows popping up.
I think I have partially resolved this for myself by opening (and purging) Libre Office, not from the shortcut I pinned to the taskbar at the bottom of the screen, BUT by opening Libre Office from the list of Applications that appears on the left sidebar via the Windows button.
Then a number of files are displayed which, when too numerous, block the Application. They need to be (removed) purged by clicking the x on each of them regularly.
I haven't found the simple solution to quit "cleanly" Libre Office, so that the VIEWED files don't pile up in the Application.
Maybe someone knowledgeable on the subject will give us the key HERE.
Best regards.