There is some odd Win 10 bug with the way the start button lines up with large taskbar.
Using example 40 pixel large taskbar height with start button 40 pixel,
the horizontal line on button did not match taskbar line, and drops down one pixel line.
I had to cut a one pixel line off button and move up to match again.
If my system is different than yours, you might need to edit the buttons back to normal.

