Thunderbird reprompts for the same working IMAP password

[ese002]

After the last update to Thunderbird 78.13.0, I have noticed that it seems to periodically forget my IMAP password. It stops polling for new mail. Then when I click on a folder, it prompts me for the password again. I type it correctly, just like the previous time, and all is happy for a while. It polls for new mail without any required intervention on my part. An hour or so later, the process repeats. Thunderbird does ask me if I want to save the password. I really don't. I just don't want it to forget the password is already has in memory while it is still running.