I would appreciate any insight I could get from anyone on what may be going on and how can I resolve the problem.

Thunderbird, with the latest update, will decide on its own who moves some inbox item or two to the archive file without me doing anything. When I discovered the emails in the archive file I can move them back to the inbox without any problem but I would like to stop Thunderbird from sending anything to the archive unless I tell it to do so. I would appreciate any insight I could get from anyone on what may be going on and how can I resolve the problem.