Mouse position lags behind cursor in editor if framerate drops. This can be especially problematic for individuals who quickly select assets as the mouse position may lag behind the cursor location and cause user to select incorrect assets, etc.
Depending on mouse location when click occurred, the mouse click may select an incorrect asset. Even if the correct asset is selected, the image will drag behind the mouse location incorrectly.
The mouse always selects the clicked asset and the asset's icon remains with cursor.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-28113 in the post.