Have determined its a codec issue with browsers. Don't know why I didn't try this in the beginning = just opened the video file directly with chrome/firefox - same issues.
The issue is that I'm using sonarr/radarr and this is stuff that came in with them. Seemingly a lot of dropout content for some reason.
Is there a way to just say no remuxing - if you cant direct play transcode the damn thing.
Tried updating the user permissions but that didnt seem to work.
You can use Tdarr to automate pre-transcoding everything.
Jellyfin will remux or transcode when the client needs it. There are edge cases where it does either needlessly (misconfigured profile), but most of the time remuxes and transcodes happen because they need to.
Jellyfin 10.10.1 (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)