I had Chromecast issues and now, I've found out something, that I didn't realize I'm In-gearlier.
When I'm In-game, sometimes my stream freezes and crashes. When I press the Stadia button on my controller, I can still navigate through the Stadia in-game menu without input lag, so my controller has a working connection. After 20-30 seconds, my CCU says "link a stadia controller" and shows me the pairing button combo, even if my controller is still connected and didn't disconnect. If I'd try to restart the controller to repair it, it wouldn't be able to reconnect to my device and even if it would connect, the "link your Stadia controller" pop up wouldn't disappear.
Usually, I factory reset my CCU+Controller or restart it when this happens, but this time I opened the Google Home app and pressed the "quit stream" button. My controller stayed connected, despite Stadia was denying it. When Stadia closed, I could simply restart stadia via controller, so my controller definitely has no issue and it's the Chromecast having issues.
Please fix this @StadiaTeam, I have to do this way too often. Sometimes it's once a day or even multiple times a day. Despite this, it's running extremely good on my CCU. Is there any way to help fixing this?