Transcoding takes 100% CPU then goes Buffering

[dynux]

Are we talking 100% of a single core or 100% of the entire CPU?  The audio is transcoding, which will always occur on the CPU.  The video is transcoding via NVENC.

Also, are there other background tasks that are still running that are contributing to the CPU usage?

For the record, you can check every codec box.  Both decoding and encoding.  And ensure tone mapping is checked.  The 4000 series RTX cards support everything.

thanks for your fast reply.

Here is the the CPU while playing the video:
   

Enabling all the settings you suggested has solved the CPU usage, on the Smartphone is all OK but the tablet still buffering even worse than before:
   

Data from Jellyfin app on tablet:
   

Seems that not only audio is not supported, also video from h265 to h264.

Any ideas?
Thank you