I've had the joy of raising two litters of chihuahua puppies. And, I've noticed that for a little while their ears stand up perfectly, but then they seem to "outgrow" the puppy and flop over again for a few months. Rest assured, though. Several of the puppies' new families were happy to send me pictures when their new babies were around a year old, and all of them had perfect 10-2 "radars" like Mom and Dad. Good luck!