After seeing aboves (’ post) debug, I went ahead and renewed the libOpus library.
That had no effect either. However as DX11 is listed in the call stack, we tried to package our project for DX10 and DX11 and use the -SM4 command.
We had 2 hours of non-freeze and then closed the game on our own.
No time yet to continue testing, but maybe you peeps could test that on your end too? (: