There is a fitting inside of the mirror body. It is a ball and socket arrangement. The breakaway fitting rarely gets loose. The socket which the stalk goes into can get loose inside of the mirror. Disassembly of a mirror itself can be tricky. The housing snaps into the glass frame and can easily be broken when disassembling. Some models have little screws as well. I think yours is a one piece housing. Two choices, get used to it as long as the mirror stays where you put it, replace it or try and fix it. Whoops three choices.

__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.