I have bought a new Cx-3 and the mirror are not closing when I lock the car. I’ve seen different videos but none seem to work.
I don’t have a specific button, but I can’t close them manually so I guess there must be a way?

 

On my CX-5 if you rotate the button past the R(ight) position the mirrors fold. You may want check the settings on your car, I think the folding mirrors can be turned on and off. Probably in the section where you can adjust the auto lock settings.