It has comes off and, with a lot of work and four letter words I can get it back on. But after 1 or 2 days it comes off again. This leaves it so that it is very loose and it starts pointing down as I go over bumps, as well as the little ring has an annoying rattle as you drive. I don't know if I need to take the whole mirror off to permanently fix or if there is some trick to doing it while it's still on the car. I see that there is a small gap that allows it to spread open, I assume that gap is supposed to be there. I also don't know how to tell when it is actually fully on. Anyway,has anybody had this problem and successfully fixed while it's still attached to the windshield?

2015 4 Door S.