I had a similar issue after installing the last Win10 update. But it only happend on my second screen and the pixels where much smaller. I unplugged the screen rebooted PC and plugged it back in. That did the job for me. But if that works on main screen I can´t tell.
Wow the last update has really caused issues, my graphics card decided to no longer use RGB but use YCBCR 422 instead causing weird colouring. Changed it back and all was well but, wow, when are the updates going to stop destroying our systems.