In 8 months, is there regression in sleep or a jump in development? ? …

In 8 months, is there regression in sleep or a jump in development? ? He sleeps during the day barely, and then he can go from 4:30 PM to 9:30 PM and then falls asleep with tantrums. Although I'm putting him to sleep for a long time, I think maybe he will fall asleep. Never had such a thing, always slept for 2.5-3 hours. And for the last week, he refuses to sleep. He plays on the floor, cries more often, screams. Could it be that he learned lullabies? Or did his tooth erupt? I'm exhausted all day alone, even when he sleeps. Did you have something like this? Day