I'm having the same issue as the OP. I had a '15 cougar and the mirror never clouded, I have washed the Alpine 1 time with the same soap I used on the Cougar, (Meguires Ultra Gold wash and wax), and the mirror has become very clouded, I don't think it's from washing it. If I have to take the trailer in for any warranty work I'm going to ask about it.
I didn't use this mirror at first either but once I realized that looking in the rear view mirror of the truck was a lot more comfortable than twisting around to look out the rear window I got spoiled.
