Not responding after some time in windowed mode

If I play BeamNG in windowed mode and then click on another window, the game sometimes stops responding. Not always but pretty frequently. It started this morning out of nowhere. I'm modding the Pigeon at the moment and every time I click on notepad++ I fear it will crash the game. It can be closed in task manager and results in report like this.

It uses about 500 to 600mb of memory when it stops responding and I do have about 50% of my 8gb of memory free.
I have disabled (moved to another folder) all mods and my overclock on my graphics card. Also deleted the 0.8.0.1 cache folder manually.

EDIT: okay now it happens every time I click outside the window :|

EDIT2: and now it doesn't happen at all???? I'm really confused but happy