Nobody answer so I finally succed on my own.
So I will share for the others with the same problem. It seams that there is a bug, that if you have several fragments and you try to instanciate two or more maps (Google Maps) seams to take the same instance previously saved, even that you use SupportMapFragment.newInstance()
Anyway, what you should do is always close the map before open a new one, so if you want to show the second map, first of all remove the fragment with the previous map. And then instantiate a new on and add to the correspondent layout.
It's not a really good solution because it means to open and close the maps everytime, but is the best I could find.