I'm using a OnePlus 6 and have been playing games with the touchpad for several days and decided to buy the stadia controller. I'm using a usb-C male to male cable and it won't synch to the app for some reason. I can see the controller in controllers tab and it vibrates when I plug it in, but doesn't actually synch.
I switched the male to male cable for a USB-C to type A converter, and turned on "OTG storage" in settings and I'm good to go. Not sure why a Type C cable alone won't work.