Yup! That’s the worst thing that can happen. Now would you be so be kind as to send us the link to your private unsecured Jellyfin server?
My advice as someone who’s server is so large backups aren’t feasible at my price point. Ensure that things you care a lot about, photos, family videos, tax information, things that can’t be replaced have a proper 3-2-1 backup solution and test it periodically. Nothing worse that putting all that effort into a backup then not being able to recover.
I do not recommend backing up media, like movies, TV shows, audiobooks, and music. Use a 2-1. Have two copies of the data with one offline. I have over 20Tb of high-res media and it would cost more than it’s worth to me to backup that stuff. So I don’t. I can just redownload The Lord of the Rings, I can’t redownload the video my parents took of me in a childhood school play.
Yeah docker isn’t the isolation sandbox some people make it out to be. It’s not meant for that. You very well may have a setup that’s meant for that but it’s more than I’m willing to expose.