Tested again. Still the same Map problems on my Card, and a friends laptop. Mine is an older AMD card, his laptop is also from 2011 AFAIK.
Also we found a funny bug, where when the ingame time reaches 00:00 (we started around 21:00) the skybox kinda starts to freak out. the skybox started spinning around the north star for with the speed of 24 hours per second, so every second the skybox made a full day/night cycle
was kinda annoying for the rest of the game cause it didnt stop.
Also for the friend who joined my lobby the depth echo didnt work, no idea why.