The resize borders of MetroWindow make part of the title bar unclickable

[WoKavo]

Hello.
When ResizeMode property of MetroWindow is set to NoResize, the "resize borders" become unclickable and you can't move a window when you hold mouse button on title bar on that area. Close button also loses focus before cursor is moved out of its borders. It gets especially noticeable when you decrease the height of title bar and half of the title bar might get unclickable because of these borders.
A default wpf window doesn't have that kind of behavior.
Is this intended and is there any way I can get rid of this behavior?