Fast heavy breathing at night - 10 week old puppy

Hi everyone, I am hoping to get some reassurance from people that have already experienced this with their puppies. I have a 10 week old male Goldendoodle that is happy, playful, eating well and handles exercise well. I brought him home last Sunday and the next day I noticed he was breathing fast and heavily while taking a nap. I was not too worried since he was still anxious in the new house and was still getting used to me. I took him in for a routine check-up and the vet said that his temperature is fine, heart and lungs sound good and that his gums are the correct pink color so he is probably not having respiratory issues especially since he has lots of energy and does not get out of breath when playing. While this does not happen as often during day naps, he still gets does it at nights. About 15 minutes into his sleep, he starts breathing very fast, about 80 breaths per minute and when I try to comfort him, it does not help. His breathing eventually slow down in about 30 minutes to 2 hours and he begins to snore sometimes. He still seems a bit restless through the night even when his breathing slows, sometimes he wipers and twitches but I know that puppies dream a lot. He does not cough or sneeze. I read somewhere that this is what puppies do in their sleep cycle and that they are growing but I wonder if this could be a neurological issues or maybe just anxiety? He does not seem anxious or abnormal during the day while he does get startled by noises, otherwise he is happy and playful. I appreciate any input that you may have.