Sounds like a plastic lug has broken off inside or something 😳.
Or if you're lucky something has come loose and could be reattached if you can get inside it.
I imagine this has started happening spontaneously, you haven't had someone clip your wing mirror while out driving, or you've come back to the parked car and found the mirror in that position?

 

Thanks

That's what I'm thinking also.

Time to remove it and have a closer look!!

Paul

 

Good luck!