Boot camp update broke Windows 10 resolution

I too had this happen to my 2014 Macbook Pro. To fix it do the following:

1. Right click on the desk and choose "Display settings"
2. Click on the "Advanced display settings" link
3. Click on the "Advanced sizing of text and other items" link
4. Click on the "set a custom scaling level" link in the "Change size of items" paragraph
5. Change to option in the drop down to 100%
6. Log out and log back in

i had the same problem. You can fix it with right-click on desktop -> displaysetting (second last sign) -> screen and control the size

if the resolution is set to 1920 then likely you set the dpi to something much higher then 100%