... Also my Mannequins in my raven rock house actually move around...
Annoying little wanderers.
There is a fix, though.
- Click where the mannequin is
supposed to be; you'll get a cursor
- Remove an item, stay in the menu and give it right back
- Exit the menu and the mannequin will snap back to it's pedestal
The mannequins should then stay in place. At least they have for my characters. Your mileage may vary.
Hope that helps