More information: System Runtime Diagnostics: https://paste.ubuntu.com/p/W7GHMhMq9V/

The streaming_log.txt from ~/.steam/steam/logs/ would almost be more helpful than the system diagnostics, fwiw. I have a suspicion of what's happening, and the streaming_log will confirm it if so.

(Basically if the streaming log says the capture session is "Desktop Black Frame", that means that for some reason Steam couldn't find a valid way to capture the screen.)

I've found after lots of experimenting (thanks AI) that basically what helps is turning off nvidia "allow flipping" option in nvidia settings.

I had the same black screen with sometimes one frame, sometimes garbled input, with visible cursor but no actual streaming and most of the time black screen (random) on desktop.

The effect was on android steam link, ios steam link, steam link physical device, meta quest3 steam link.

I've tried everything: changing resolutions, encoding options, refresh rate, hardware encoding, network QoS options, anything and everything.

Black screen with Desktop OpenGL NV12 streaming. The games where fine since they were using some delayed overlay capture. The problem was clearly on linux (Mint 22.3 Zena). Both cinnamon and kde plazma both on X11.

I still get this error sometimes (i have switched to an AMD card for compatibility reasons) but it helps if I turn one of the dual monitors off.