With TV Screen SOMA doesn't start/get's aborted

[Hairy Crews]

Okay, so, it's a little complicated to explain.
I THINK I tried everything in the Troubleshooting Guides and didn't miss anything and of course did further googling.

I bought SOMA on Steam. When I start it running with my Desk-PC-Setting (simplicitywise i call it that now), so 2 PC Monitors plugged into my GTX 1080 ti, everythings normal.

BUT I really (really!) want to play it on my 4k OLED TV which I plug into the PC via HDMI whenever I want a more cinematic experience. Therefore I simply plug out the monitors, so the TV is my only "monitor".

Because of the 4k Resolution I have the DPI Scaling on the TV Screen set to 300 %. But even when I set it to the standard 100 % before starting SOMA, before even getting into the game, it get's aborted with a generic error message, saying it had to be shut down.

Also tried the compatibility options when right-clicking on the exe (the NoSteam.exe as well), but still nothings working.

The ONLY thing thats working this far is having all 3 of the screens plugged in, so the TV is the 3rd and setting the DPI Scaling for it down to 100%, THEN starting SOMA, setting it to Windowed Mode and pushing the Window over to the TV Screen. THEN I can set it in-game back to Fullscreen and it's working as it should. But that's a highly unsatisfying solution. There just must be something else! Please help, guys. And thanks in advance.