Multiple problems after Thunderbird update. On two separate computers, mine and my wife's. Ubuntu 20.04 LTS desktop, Ubuntu updated Thunderbird last night to 91.5.0 (64bit). Consulting dpkg.log shows the previous version installed was 78.14. These are distributed by Canonical. One of my accounts and all it's folders and sub-folders disappeared. Same on the second computer with many more folders in the deleted/missing account. My filter entry to move some incoming messages from extant account to the disappeared account now unchecked. Have not checked other computer, but expect same behavior. Many messges to one of my local folders sent to spam. Also new incoming to my one "good" account going to spam. First, what happened with the new release? Second, any chance to recover? There are backups of the .thunderbird files