Do you have issues with all clients or a particular client? The ffmpeg log you shared doesn't indicate any transcoding issues. And the transcode output is nothing unusual in terms of codecs.
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)