Oh. Found something new I didn't notice. In the Network tab of Resource Monitor there is a "Listening Port" that also includes the firewall status. What do you see for yours?
Jellyfin 10.10.3 (Docker)
Ubuntu 24.04 LTS
Intel i3 12100
Intel Arc A380
OS drive - SK Hynix P41 1TB
Storage
3x WD Red Pro 6TB CMR in RAIDZ1 (JF Library)