Borderless window application takes up more space than my screen resolution

Question

I have created a borderless application in WPF, and it works pretty good. However, when I set the WindowState to full screen, the application takes up more space than my scr

Answer 1

I found this great solution

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But error for me still persists, windows is offset by few pixels on top and left... I tried to set Left and Top to 0 after I change window state but nothing happens.