On Drop Function registers on wrong widget? Widget scaling beyond what is visible?

Interesting, I just reset the Drag visual to None and now everything is working… What do you usually use instead of self?

Edit: Okay I now made a DragVisual Widget (just a simple size box containing an image, both not hit-testable), that gets created before creating my Drag and Drop Operation. Appently that does the trick.
Thank you for your help @rokenrock !