It would have been highly beneficial to provide a function or procedure to migrate all files (if they existed) from org.mozilla.Thunderbird to org.mozilla.thunderbird. In the absence of such a mechanism, the update effectively behaves like a fresh installation, creating the impression that all user settings and data have been lost.
I resolved the issue by manually copying all files from /home/USER_NAME/.var/app/org.mozilla.Thunderbird/ to /home/USER_NAME/.var/app/org.mozilla.thunderbird/ and restarting Thunderbird, after which everything functioned as expected. This could also have been addressed through a symbolic link to the new path.
I believe more care should be taken when implementing breaking changes of this nature, as many end-users would not know how to resolve this issue on their own. Clear guidance or automated migration would help prevent unnecessary disruption and confusion.
