Ok. I looked over your logs again. The ffmpeg lines in the main log that are failing are transcodes, but all the ffmpeg files you've shared are remuxes.
In the log directory there should be ffmpeg logs with "Transcode" in the file name. Can you find and share one of those?
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)