A bug I'm unable to debug

I’m trying to build a drag and drop tool for perspective. I have it working almost perfectly except I am randomly getting this bug pop up. If I grab the element in just the wrong place, then instead of dragging it, it just wiggles a little and the cursor changes to something I didn’t program in.

I don’t know what this cursor is or why it’s happening. I don’t get an error popup like I would for many other errors, but I am getting something print to the console, but I don’t know what it means.

DragAndDrop_2021-05-07_1740.zip (26.1 KB)

Here is an export of the relevant code.