iPhone to Host Blacksreen (only works when Host screen turned on once)

[Minsekt]

ive got this Blackscreen issue whenever i try to connect to my PC.

ive nailed it down to a resolution related problem:

It only works after turning on (physically) the screen/monitor of the host. which is obviously impossible when away from home. i start the host via WoL. Teamviewer is working right away, steamlink just shows a blackscreen. i tried to trigger it to work by changing desktop resolution, starting games in fullscreen/changing resolutions ingame etc. (all via teamviewer)
but the only thing that makes the blackscreen go away is turning on the Screen. (i can see the cursor though, and also the changes of the cursor, like loading circles, when im hovering text or theres a custom cursor ingame)

any idea what that could be or how to go around it? seriously thinking about a remote servo that physically turns on my screen lol, but that must be easier... seems like a bug. tried stable and beta but all the same.