I had a rough time with Jellyfin like 6-7 years ago, with media not populating/playing properly, and metadata being lost on upgrade, etc.
Tried again a few months ago and couldn't be happier. The whole thing is very stable and reliable. I think my only annoyance is that the HW I have it running on isn't beefy enough for transcoding, and my LG C4 can't play some of the 4K codecs natively (particularly around DV). Obviously this isn't Jellyfin's fault, but this kind of thing is just one more item for the list of stuff to have randomly be a surprise when setting up this kind of thing.