Harvey
Hi thank you for this update of Thunderbird, however, since the update all of my pre-configured outlook accounts stopped working.
Bu I have now fixed this by checking the IMAP settings and SMTP settings, the authorisation method set in Thunderbird was set to "Normal" this needed to be changed to "OAuth2" once this was done I received an authorisation request via MS Authenticator and all is working again.
I thought that I would share this in case anyone else suffers the same issue.
I got this information from the Thunderbird support page:
https://support.mozilla.org/en-US/questions/1406094