Maybe it's a Linux thing?

I've been using it on Windows for years with multiple devices and it's been working flawlessly.

It has worked flawlessly for me on Linux.

Could be, but it also had problems on my mac. I had to abandon Jellyfin for Emby over it.

Every so often, Jellyfin would choke ingesting a video. Worse, it would hang the whole ingestion process, so videos later in the list wouldn't get processed. Restarting didn't fix it, either, I had to delete the problematic video (which notably, played ok in things like VLC and IINA).