I solved the problem. It wasn't in the BIOS (I even updated to the newest version) but a setting in Windows 10.
I found the solution in this community topic: https://communities.intel.com/thread/43924?start=0&tstart=0
The solution given there was for Windows 8, but works the same in Windows 10
Thank you for contacting the Intel® Communities.
I am glad to hear that you were able to fix the issue with the other thread.