I haven't gotten this to work once after hours of troubleshooting. Fresh install of PI OS, I setup the PI over VNC, and install steam link. When I run it, it updates and installs dependencies. I pair the PC and connect. When I connect, Steam launches and runs fine on the remote PC, but on the pi, it just shows the PI desktop with a terminal window in the middle that shows some diagnostic info. And the bottom 10% of the screen turns black. The only over thing I did to the PI was changed the resolution from default to 1920x1080 in "raspi-config". Everything is up-to-date. I tried toggling all the advanced streaming options on the host as well. Disabling VNC on the PI, messing with different resolutions. Even reformatting the PI and starting over.
I don't think it's an issue with the remote PC because everything else can connect fine.