Bedtime going wrong

So my baby is 16 weeks. The last few weeks she is waking an hour after putting her to bed. She will only settle back down if I put her on the boob for 5 mins then she’ll drift back off

Before bed I feed her, get her super drowsy then swaddle her and put her to bed.

She’ll usually wake twice. So once an hour after putting her down, then again an hour after being put back down.

Anyone had anything similar and can offer advice?

Tonight I put her in her crib wide awake babbling to herself and she drifted off on her own, which is a first. But still woke up an hour later

Could this be the 4 month sleep regression?