Rhino.Input.Custom.GetPoint events seem to suspend in some cases

I am using the events in .GetPoint() to draw things during mouse move. Everything is working except when the mouse point gets close to the camera plane in perspective view, the events seem to stop firing. Below is python code that demonstrates what I’m seeing. If you navigate the camera close to the world XY plane, then move the mouse up/down, across the plane, the events seem to stop and the mouse x, y won’t print. Also the crossahairs drawn by .GetPoint() will stick.

I’ve googled around, and tried various parameters but can’t seem to find a fix. Any help appreciated.

import Rhino
import rhinoscriptsyntax as rs
import scriptcontext as sc

def handle_mouse_move(object, e):
        print(e.WindowPoint.X, e.WindowPoint.Y)
    except Exception as exp:

def demonstrate_get_problem():
    getter = Rhino.Input.Custom.GetPoint()
    getter.MouseMove += handle_mouse_move
    # getter.DynamicDraw += handle_dynamic_draw
    # MouseDown += handle_mouse_down
    getter.Get(True, False)
if __name__ == '__main__':

The option .ConstrainToTargetPlane() is what I was looking for.