I have a WUHD monitor (5120x2160) with two machines attached, a Linux Desktop with an RTX 2080 and a Windows Desktop with an RTX 4090. I am using Remote Play on Linux to stream games from the Windows machine. I have found that this only works if both machines have the resolution set to exactly 5120x2160. Otherwise, I just get a screen that is black other than the mouse pointer.

Some games work perfectly. (Hades 2, Europa Universalis 2, Rimworld and Factorio for example.) But many games just give a pure black screen at startup. This happens in every game with a launcher (Stellaris and Crusader Kings 3 for example.) But it also happens with many other games. (Doom:Dark Ages, Indiana Jones are two examples.)

In some cases, games will stream fine if I launch on Windows, then switch to Linux and Connect to the existing instance. (Stellaris, CK3 and Doom: Dark ages are examples). But others, like Indiana Jones just don't work at all. That game doesn't seem to support 5120x2160.

My supposition is that if the video mode changes from native at any time during the game's execution, streaming breaks.

I am nearly certain this doesn't have to do with networking as for games where streaming works, it works well. Both desktops are connected via physical 1 gig ports. I also don't have any troubles streaming to my Steam Deck