Well I already have jellyfin running in a container, just have to figure out how to get mum's TV to work with it I guess
log in on a local IP and not the network name and it's working again. but I'll be moving to jellyfin from now
How to migrate your watch history, apparently: https://www.florianjensen.com/2024/08/21/how-to-migrate-from-plex-to-jellyfin/