I made the pro subscription for a few days I can no longer set the 4k resolution,
althoug at home I have 50mbs with the ethernet cable and until a few days ago everything was fine,
now I can no longer activate the 4k nor the HDR with the Chromecast ultra It Is very frustrating,
I would like ti know why?
They did recently change how to set your resolution, are you trying to change it using the app or are you pushing the stadia button to do so?
I am using the app
@Babaganuche7 has hit the problem on the head. There is now a way to change resolution for each device you use.
Rather than in the App, you need to change the resolution on the Chromecast.
Changing your resolution on a Chromecast Ultra device