I noticed in your signature that you have a PiHole. I don't see why going from 10.8 to 10.9 would change anything, but maybe this is a DNS related problem and the PiHole is the cause?
Jellyfin 10.10.7 (Docker)
Ubuntu 24.04.2 LTS w/HWE
Intel i3 12100
Intel Arc A380
OS drive - SK Hynix P41 1TB
Storage
4x WD Red Pro 6TB CMR in RAIDZ1