4K Movie Playback Issue on Firestick 4K with Jellyfin

[Sunkiller-qc]

This issue respects the following points:

• This issue is not already reported on GitHub (I've searched it).
• I agree to follow Jellyfin's Code of Conduct.
• This report addresses only a single issue; If you encounter multiple issues, kindly create separate reports for each one.

Describe the bug

Hi,

I have a Jellyfin server used by more than 40 people, and I’m encountering a specific issue with users who have a Firestick 4K. When playing 4K content, they get a black screen, even though the server shows that the playback is progressing (the seconds are counting normally).

There are a few temporary workarounds:

1. Skipping forward or backward by 30 seconds makes the video display correctly, and playback continues without issues.

2. Reducing the bitrate limit to 5 Mbps forces the Firestick to request a 1080p version, which resolves the issue, but it’s not a true solution for 4K content.

I want to point out that the server does no transcoding, and all other users—whether they are using Android TV, Nvidia Shield, or web browsers—don’t have this issue with 4K playback.

Does anyone have an idea about the cause of this behavior or a more permanent solution to avoid these workarounds? Is this a known bug with Jellyfin on Firestick 4K?

Thanks in advance for your help!

Media info of the file

Client logs

No response

FFmpeg logs

Application version

0.18.4

Where did you install the app from?

Amazon Appstore

Device information

Fire stick 4k max

Android version

Fire iOS 3

Jellyfin server version

10.10.3

Other sources

No response