Dear Samsung Member,
Greetings from Samsung Customer Support!
Please perform the below mentioned steps to resolve the issue:
* Check app cache:-
Clear cache memory of a particular application : Setting >Apps >Now pick the app. For example 'Samsung Internet' >Storage >Clear Cache.
For further assistance, register your concern in Samsung Members Application (Open Samsung Members Application > Get help > Send Feedback > Error report/Ask questions).
Thank you for writing to Samsung.
Samsung Customer Support
I have the same problem and unfortunately HDR videos on YT are lagging and skipping frames on 720p/1080p/1440p HDR content. Only 480p HDR on YT works fine however my S8 is very hot during 480p playback. I have tried reinstalling my YT app and evrn clearing cache, but nothing helps.
I have no ussues with standard 1440p 60fps SDR playback on YT, and even downloaded 4K HDR videos works fine, but there's clearly something wrong with YT HDR videos. If S8 is too slow for HDR playback on YT, then people should be at least able to turn it off like on phones without HDR support.