Never ending sleep regression?

Lena

So my son started to have sleep regression at 3,5 Months old. He was awake almost every hour and some night even every 30-45 mins. It lasted for about 3 weeks. Then he started to sleep way better (3 hours stretches for about 5 days) and now again the same thing up every hour. It’s like a roller coaster you never know anymore how long he will sleep this night. Is it normal? He is 4,5 Months now.