SOLVED: 4K HEVC HDR not decoding in WebOS app

[DrGoldberg]

Hi!

I'm using Jellyfin 10.8.13 installed on Windows 11 as Windows Service on an Intel NUC with an 12th Gen Intel Core i7-1260P with it's GPU Intel UHD Graphics Version 31.0.101.5084 and 16GB RAM.

Now I can't play 4K HEVC HDR content on a 1080p LG TV with WebOS. On this TV the Jellyfin app from WebOS is installed. I always get the error "This client is not compatible with the media and the server is not sending a compatible media format".
When playing the content on a TV that supports 4K I have no problems playing it.

It is also not working when using Google Chromecast on that TV.

I think the transcoding is not working properly.

Hardware acceleration is enabled with Intel QuickSync (QSV)
Transcoding settings:

• Hardware acceleration: Intel QuickSync (QSV)
  
• Enable hardware decoding for: everything
  
• Prefer OS native DXVA or VA-API hardware decoders: true
  
• Enable hardware encoding: true
  
• Enable Intel low-power H.264 hardware encoder: true
  
• Enable Intel low-power HEVC hardware encoder: true
  
• Allow encoding in HEVC format: true
  
• Enable tone mapping: true
  

All other transcoding options are as per defaults.

Logs are attached.

Hope you can help me with this problem.

greetings