4 month old sleeping issues

Hi,

My baby boy will be 4 months next week and he’s been struggling for the past two weeks to stay asleep after being put down on his bassinet. He usually goes to bed by 9:30pm and sleeps till 7am with one night feeding which is great but I notice that he gets sleepy around 7pm and we try to put him down to sleep then but keeps waking up every 20 minutes or so or immediately after being put down in his bassinet. 🤦🏽‍♀️ bedtime is a 2 hour thing now and it sucks. Is this happening to anyone else? Is this a phase?