In Thunderbird 91.11.0, to move an email from my inbox to an archive folder on my hard drive, I right-click on the message and click on the Move To option in the pop-up menu. From there, I click on the location where I want to move the item. After doing this, the item is gone from my Inbox folder, but remains in my All Mail folder. If I move it from my All Mail folder, I now have two copies in my archive, yet the original still in All Mail. So the Move To option is behaving the same as the Copy To option.    My work-around is to move the message to my archive location, then right-click on the message in my All Mail folder and select the Delete Message option in the pop-up menu.    Is anyone else seeing this behavior?