When form is maximised the form overlaps onto either side of the monitor. A part of the form is cut off on both the left and right sides of the screen. When using multiple monitors the form overlaps onto the monitor screens on either side of the main screen.
Screen shot of both primary (left side)and secondary (right side) monitors. The right part of the form is drawn on the secondary monitor.
This happens on various PCs running win 7 and win 10 on .net 4.7 framework.
When form is not maximised the form is rendered correctly.