SOLVED: 4K transcoding issues (New jellyfin user from emby)

[thymon]

Hello,

I recently switched from EMBY to JELLYFIN, and since then, I’ve had persistent playback issues with 4K content. These issues were nonexistent on Emby.
The GPU transcoding is functional since I have no issues with 1080p content.

On the Jellyfin iOS app in direct stream mode, the media starts but stops after a few seconds, leaving me with a black screen.
The same media in direct stream mode on the Emby app plays without any problems.
When I force transcoding at a lower bitrate, the media starts but freezes after a few seconds, or I experience skips of several seconds forward with audio desynchronization.

Performing the same test on the Emby app with forced transcoding works flawlessly.
Both Emby and Jellyfin are running in Docker on Unraid.
An NVMe drive is used for the transcoding files.

Here are the log files, in case they help.

Thank you!

[thymon]

I'm such a fool
Upon carefully rereading the logs, I realized I installed the Transcode Killer plugin.
That's the culprit