Option+Drag "green circle-plus" icon issue

Recently I've noticed that the green circle icon (with a white plus sign in it) that appears when you option-drag a file in finder for copy, doesn't work properly for me. It appears only for a fraction of a second when you option-drag and disappears again, only coming on for a millisecond when you drag and move around the file then going out again. Its a bit annoying and can't seem to solve the problem.

What controls that icon and what could be the reason this is happening?

Thanks.