When doing a right click outside the window while the mouse is (auto-)grabbed then it will still show a context menu

When doing a right click while the mouse is grabbed then it will still show a context menu. However in comparison to native windows this should not be happening.

In the example attached, start to resize a header section and move the mouse out of the window (holding the left button down). When outside of the window, right click (while still holding the left button down) and then the context menu will appear.