So, with Valve's hardware announcements, I wanted to try some game streaming to get an understanding of the limitations of this feature but it didn't work right.

I went to Stream from my PC to my Steamdeck that was docked (for clarity, game runs on PC but is seen and controlled from deck). I have messed with the stream settings on both ends, but what I get is the upper-left corner of the display on my PC inflated to the size of the full screen on my Steamdeck.

Both devices are currently connected to 4k displays and I have them set to use the full display. My expectation is that if the network bandwidth is insufficient, it should still display the full screen, but at a lower quality. It seems like it's keeping the quality and streaming only a portion of the source image instead.

I also reversed the stream and had no issues going from my Steamdeck to the PC; everything worked.

I'm thinking that the issue is on the Steamdeck end and it sees the built-in display and somehow uses that to cap or resize the stream before it ends up on the 4k display. This is supported by the issue not being present if I stream to the deck while undocked.

Admittedly, my PC is weird since I have Bazzite instead of Windows. Still, it works the other way around and I think linux-to-docked-deck streaming will be more frequent after the launch of the new hardware.

If there's a fix or this is a known issue, please let me know.