5 month old went from only waking up once a night to waking up every 2-3 hours again

I keep thinking were done with waking up multiple times a night but it keeps going in phases ☹️ he'll sleep amazing, getting up once a night to eat for a week or 2 then goes back to getting up 3-4 times a night. There's no changes in his day schedule, we have a night routine and he falls asleep same time every day

Just feel defeated, I'm exhausted