If its a JCB branded hitch, they have a control box mounted on top of the dipper. Do you still get the two tone buzzer that tells you when the arm is in the right position?
If you do, then the little ball bearing in the control box is probably fine. But many people short the wire out so you can take the bucket off in any position.
But what many people don't know is there's another little ball bearing in the hitch that gets sticky if you don't use it regularly. I find shaking the bucket before crowding it right in to open the hitch seems to sort it.
You can take it apart and give it a polish up but regular use seems to help sort it