Fullscreen questions (4.4.1)

Hey guys, I have tested out Fullscreen in my example map but I can’t get it to work. The first thing is when I’m in the launched game and I hit Alt+Enter it will switch to fullscreen, but with a bad resolution like 800x600 or so. So my second test was to try out this r.FullScreenMode command. But r.FullScreenMode 0,1, and 2 don’t affect anything even when I go out of fullscreen and jump in again. And then, the r.setRes does nothing in fullscreen to (in windowed it works quite good, but in fullscreen nothing happens)… Do you can help me? Oh and is there a way to go out or go into the fullscreen with blueprints? Thanks!