Dxdiag and config looks fine, same hardware setup I had last month (GTX970) as well so can rule out any issues there
Below is a new build which will output all displays it can find to the debug.log including their indexes, also a few other things to try:
- System DPI is currently set to 144 DPI and while I don't suspect this can interfere with capture would try it with 100% (no upscaling)
- Would try english language / locale, while unlikely we can then rule that out as well.
Download link for debug build: