SOLVED: Can't connect remotely to Jellyfin using Tailscale

[gmachine24]

  jellyfin.logs.tar.gz (Size: 35.37 KB / Downloads: 40)
I gave up on this thread https://forum.jellyfin.org/t-database-sc...-malformed
as there were no replies.

And I thought I'd try to run Jellyfin on Fedora 40 because I basically think Fedora>Ubuntu. Mostly, anyway.

I installed Jellyfin on my Fedora 40 desktop, scanned one of my music folders and no db errors- this was a major win as every attempt to run Jellyfin on Ubuntu ----> corrupted database without recourse.

Jellyfin behaves well on Fedora so far. Two scans and no complaints about database errors. So I moved on to remote access.

I installed Tailscale on all my phones, the Fedora 40 machine, the Ubuntu server, and an iPad.

I had some luck gaining remote access to Jellyfin with a phone when it was connected to the Internet via the Verizon network (it's actually a Tracfone); a bit less luck connecting on my T-Mobile network phone (actually the Tello mobile provider).

Then, today, nothing. I couldn't connect remotely to Jellyfin with any of my devices - and that includes the iPad and two phones.

I think I made sure the firewall settings are good. Tailscale was running on every device. I looked at the Jellyfin logs from the Fedora machine and could see nothing - but I don't know what I'm looking for. However, there are a few lines which I do not understand - they are like this:

"[2025-02-18 09:23:32.608 -05:00] [ERR] [104] MediaBrowser.Controller.Entities.BaseItem: Error refreshing owned items for "/mnt/MUSICBACKUP/CDs/CDs......System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/MUSICBACKUP/CDs......"

The problem here is there is only one folder selected for the library scan and /mnt/MUSICBACUP etc. is not it.

The one selected is /mnt/MUSIC1

So, beats me why Jellyfin is scanning that other mount point (which is empty)

The other side of this is that I was able to connect to my Ubuntu server remotely whilst using Tailscale from my phones. I could ssh into the server, open the Lyrion Music Server which is running (formerly Logitech Media Server and before that Slimserver).

I could not connect to the Fedora 40 desktop via a Tailscale-installed device via ssh or by running Jellyfin. Just nothing.

I think T-Mobile might be blocking access when using Tailscale as once there was a Fortinet error - saying I needed to select a different network. That's on the Tello phone.

Anyway, I don't know where to begin. Jellyfin on Fedora is running well - just to be clear. But remote access is the problem and I'm not schooled enough to configure something like Nginx.

Edit: I attached the two most-recent log files.