Drag and Drop does not show overlay for Custom Editor when drag item is not a file or an image

[ITSB-SeanLim]

When dragging element from a panel webview to another custom editor webview, the overlay message "Hold shift to drop into editor" only appears if the dragged element is an image but does not appear if the element is a div even though the mime type of the dataTransfer data is both the same custom MIME type application/myapplication.ide.flowitem. How can I make the overlay message to appear?

Attached is a video showing the current challenge I am facing right now:

Untitled.video.mp4