Can you share your logs with us via sourcebin or pastebin. Sounds like you are transcoding. Also mention which show you are having trouble with to make sure we look in the right place in the log.
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)