Help with Drag / Drop in Safari

Hi everyone!
I have a web app which invites users to drag small webcontainers from one parent container to another, and then move the small containers around within target container.

This all works fine in desktop browsers Chrome / Firefox / Edge, etc.

On iPad Safari the initial drag and drop to target container works well, but then any attempt to move the small container within the target container results in the drop receiving x,y coordinates that are nonsense (ie outside of the visible screen area and not anywhere near to the location at which the user lifted their finger to drop.

Could this be something to do with Retina screen scaling??
Any help would be very much appreciated.

Just to clarify further…
the Safari “Drop” coords are reported fairly correctly. It is the DragItem.OriginX/Y that gets crazy values from Safari.

Think I’ve answered my own question! If the dragged object is fairly small, then it’s a reasonable guess that the OriginX/Y can be estimated as being the centre of the object - therefore for touch platforms I simply substitute the Origin figures with DropObject.Sender.Width/2 etc etc.

I can confirm that works a treat.