Well I’ll be dammed. There is an open issue to support NSS for user/group info again, apparently it was removed about three years ago.
I would have started running postgres in my homelab less than three years ago, and was not using the rpm distribution of jellyfin at that time either.
So there is hope!
I was also confused for a moment due to the way my Lemmy client shows it, but op has actually linked two articles, one from 2022 and one more recent.