3am fussyness

Wondering if anyone else has a similar experience. My son is 4mo old and sleeps well. He goes down easily and sleeps all night. However, around 3 am, every night, he gets super fussy or agitated. He doesn't cry. He doesn't wake up. He just starts tossing and turning and being loud. Like a whimper lol. Sometimes we just give him his paci and he's fine. But normally he is like that until about 5 when he wakes up for good go eat. I don't think he's hungry at 3 am and I've tried before to feed him but he's honestly still sleeping for the most part. Could this just be his witching hour? Does anyone else have a similar experience or suggestions? I mean at the end of the day, I think he sleeps very well for his age but he might get a better nights sleep if I can eliminate the 3 am fussyness.