Is there a way to edit a post? My previous post said "I passed Project Streaming with an Excellent", it actually says "Great". I think in Stadia the best connection is "Excellent" which I wished (and should be getting) I had.
I'm happy to report a solution to the controller unlinking problem if you are using Google Wifi. Using the Google Wifi app, reset the network. This should stop the controller from loosing it's link during gameplay.
@Odin1 do you still have this issue? Did it ever resolve itself? I used stadia on a 60Mbps connection and it was ok. Last week I changed ISPs and now have 1Gbps. Everything you describe is exactly what happens to me since the switch. Can stream 4k videos fine, have fast connection speeds, but it rarely lets me into a game and when it does, it doesn't let me stay long. I'm really curious if this is still happening to you 6 months later. If not, did you do anything to fix it? I have spent hours troubleshooting with Google and my ISP with no success.