Every time I open Mach4 it opens as windowed as you see in the attached image. However the maximize/restore button on the top right corner is in restore state so it is actually maximized (confusing?). When I click that button Mach4 tries to make itself windowed. Then the button change to maximize state and when I click it it maximizes (truly maximized).

I always exit Mach4 maximized and expect it to start maximized.

I know its weird. Does anyone have the same issue? Is there a way to fix it?

I found the problem. Windows display scaling causes this.