How big is your library and do you have chapter image extraction enabled? It looks like it is just taking a while. No obvious reason why from the log. I just see the ffprobe messages on and on.
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