Ah. Ok. Make sure that the new adapter is set to private instead of public. The default for new NICs is to set them to public so its likely that the firewall rules for allowing Jellyfin aren't being applied.
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)