I have a R50B7120UK and a R55B7120UK and Netflix doesn’t work in 4K. It is fine for the first 15 mins and then keeps crashing / buffering. No video but audio works. I have 300 mbps fiber internet, and everything else work well except this. It’s terrible.
At this point you would think that Roku and TCL would have worked this out because it clearly is an issue that should not be that hard to fix. Is Roku or TCL technical services not reading blogs because this issue is EVERYWHERE? Maybe I will post this on their social media page next.