Baby keeps waking up at night

Is anybody experiencing the same thing? My 8.5 month old baby keeps waking up at night and can’t settle on his own. This happens irregularly - some nights every 1-2 hours, some nights he’s able to sleep for 4-5 hours stretches. He just recently drop from 3 to 2 naps (1 week ago), but even with previous 3 nap schedule he was waking up in the middle night a few times too. Especially between 4-7am, his sleep is so light I have to carry him for him to stay asleep, if not he will wake up too early in the day. He also started having preference of a caregiver putting him to sleep - when I’m not the one putting him to sleep he will fuss and cry for awhile. I’m not sure what to do 😭