The left trigger on my Founder's Edition Stadia controller just stopped working (doesn't bounce back by itself).
I want to send it in for repair or get a replacement but ... here's the kicker ... I can't find a page or form anywhere on how to get in contact with Google or where to send the controller. Can someone please help me?
Here is the link to have a live chat with support
And here is the warranty page so you can check to see if you're within the warranty window
You need to go to the Google store site and contact support from there, not from any Stadia websites. Since a controller is only $69, I doubt Google has a repair program for controllers. They'll probably offer you a replacement if you can provide serial number and order information etc.
I used the same link @Deleted User shared when I had to get my Founders controller replaced:
https://support.google.com/stadia/contact/stadia_chat
After they verified proof of purchase and all that they gave me a voucher to purchase a new Founder's Edition kit and replace the whole thing (Chromecast and all). Showed up in a few days and I sent the original back.