I ran into a similar problem when my kids bump the mirror (the actual mirror, not the housing), and it changed the position of the mirror. And she immediately pushed the mirrors back manually. Since then, everytime I start the car, it tries to move the mirror to the home position (what it remembers as home I guess), and the mirror tilts upward. I would adjust back to proper setting, saved. and on next power up, it reverted to facing the sky again, almost feels like if my daughter didn't push the mirror back in place, it would have been in the perfect position. After a few reposition saves, it finally stayed in proper settings. This was for driver side mirror, during this ordeal (a few weeks), the passenger side started doing something similar, not sure what's going on, but after some saves. both mirrors behave normally.
-ThinkMac-