Yeah, it's a common problem. I followed this exact write-up and it solved the issue 100%.
Sounds ghetto...but it works, it's free, and after you put it all back together nobody will ever know.
Put a ziptie behind the mirror on the tilt pivot area, pull it tight, cut off the exess bit. turn the locking tab part facing downward and position it and the mirror to your liking. Pretty easy fix, Ive been useing it for 6 months with sucess.