We are not talking about browser zoom (which should scale everything as required anyway) but dealing with the windows 10 system scaling issue. With say a 1200px width screen and scaling of 125% the effective width for display is 960px. Effectively each original pixel is mapped to 1.25 pixels giving a larger display while maintaining clarity. I believe the problem arises in that text and images are now 1.25 times larger but live in a viewport space that is 80% smaller than before.