When I drag something it locks and I have to click to get it out of drag, I first noticed this when I was playing on Minecraft PC and I was mining and then if I was mining a block for too long then it would carry on mining the next block; sometimes this can be useful but it can be very annoying.
This also can happen when I am dragging the screen or an item and I want to make it stop locking since this can be very annoying.
it might be because your minecraft may haved corrupted your computer