Selecting & deselecting objects is buggy too
While working in a file:
Attempting to select more than one object at a time to move them simultaneously works, but then I cannot deselect the objects by clicking the art board as in all previous versions of Illustrator.
I have to click on each object at a time to deselect them. It doesn't always happen, but it happens often enough that it becomes an issue with work efficiency.
Melinda Roman shared this idea
Melinda, looks like one of your Shift keys is stuck.
I tried to simulate that and got the same behaviour as you described.
I suggest that some app (never caught Ai on that though) must have forgot to release it. Try to restart you computer and check if it is fixed.