@JuergenR Yes have you tried relinking your controller to the app and your chromecast? It normaly does the trick. Let me know if it help.
@JuergenRI know I got that issue a few days ago I am trying to recall how I resolved it. You tried starting other games to completly flush the current stream? I know you wrote so but I want to completly isolate the possible steps I have previously taken when It happened to me.
If your response is positive would you mind trying to reset your routers and internet hub if you have one. Let them sit powerles for a 5 minutes.
I know it seems unrelated to controller but I have seen so many strange fix already.
@Northlight Yes I restarted and re-installed the system completely, also tried to start several games. Also started a game in chrome browser on my mac with the controller connected via cable (that worked), then I switched back to TV with the same fault