I’m assuming you’re just running bare-metal, in which case no GPU passthrough would be needed. From what you’ve mentioned, everything seems about right so not much more to say - But on the UI department I do agree most apps could use some polish. I’d really recommend you try to replicate, get the logs, and forward them either to the Jellyfin Forums or their troubleshooting Matrix room (or both!), as people are generally quite helpful. Best of luck!
Just to make it clear to any other people reading this, Jellyfin has Group Sync where you can create groups with participants and syncplay media.