Leaving edit mode requires second click
This is a recent regression as of 75c33e2.
Right-click any element in any score, and choose "Edit Element". Then move the mouse and click anywhere on the canvas. Notice that the ScoreView is still in edit mode, and it will require a second click to return to normal mode. However, if you don't move the mouse first, or if you enter edit mode by double-clicking on an element, it will only require a single click to return to normal mode.