I have this problem for the new Doctor Who series before it split off from the old 2005 Doctor Who series and became its own thing. Jellyfin was tagging the new Doctor Who series the same as the old one.
When IMDB finally got its own entry for the new show I was able to successfully identify the new show appropriately.
+1 for long-ass backup script. First dump the databases with the appropriate command. Currently, I have only MariaDB and Postgres instances. Then, I use Borg to backup the database dumps and the docker volumes.
Database SQL dumps compress very well. I haven’t had any problems yet