Sleep regression


My son used to sleep about 9-10 hours per night without waking up once since he was about 2 months old. Here lately he’s been waking up about 4 times and has a difficult time napping. He’ll only nap if I’m holding him and immediately wakes up if I lay him down. He’s 4, almost 5 months now. Is this sleep regression?? 😴😴😴