Try to disable scaling in your graphics card control panel. We've seen both AMD and NVIDIA has issues with it:
For AMD:
I went to AMD Radeon settings and under 'display' changed scaling mode from 'preserve aspect ratio' to 'full panel'. Worked perfectly for me. Games are running again.
For Nvidia:
I went into Nvidia Control Panel. This is where I changed "Aspect ratio" to "No scaling" on the Adjust desktop size and position page (with "perform scaling on Display"). Suddenly everything was okay again