The first few times I opened the game it started in the lower right corner, but without any Windows icons etc. Alt-Enter fixed this and took the game into proper fullscreen.
After restarting the game a few times to enter a server, I started having issues with the game not going into full-screen. When I pressed Alt-Enter it switched between two different modes. One mode with the old WIndows 7 windows buttons, stretched wide aspect ratio, and a light blue bottom bar with no content about twice the size of the Windows taskbar. The other Alt-Enter version did not have any bottom bars, but was more zoomed in, and with the regular Windows 10 upper buttons, like if I were to have Windowed mode. I did try changing it from Windowed-Fullscreen several times, no change.

I have no screenshots of this issue, I was trying to much to get into the test servers. Since this wasnt a crash per se, I guess providing crash logs arent helping. I also experienced the same Battle Eye crash after 15 seconds of playtime like everybody else.