C# stops redrawing element on canvas?

Question

WPF

There is an element on the canvas. It can be moved with the mouse.
At some point, it stops updating the drawing. So
I can see:
is it on the canvas - yes
visible is it = yes
its coordinates - yes

the coordinates change - but the position in the picture remains the same
How can this be? And in which direction should I look?

Answer 1

The cursor goes beyond the element, and so xs, little information