I could not find anyone with this issue...
I use Outlook and ThunderBird equally on a Office365-Exchange-Mail-Account. When I move one mail from one folder to another than it also does on outlook. But when I move one mail to another folder in Outlook than the mail does appear in the moved-to-folder, but still remains in the original moved-from-folder. So it actually only copied the mail.
Only fix is to shut down TB and when it starts again, it removes the mail from the moved-from-folder.
Question is, why TB does not do that automatically.
I also activated those TB-Settings (as suggested here How can I make Thunderbird IMAP sync moved messages immediately?):
I guess my only chance is to try out DAVmail, as suggested here Does Thunderbird work with Exchange account
But I still hope that there is a way to somehow force TB to refresh the expunge, so no restart of TB is necessary.