1p yr old rocking making noise @ night

So this is going to be one of those help me please I'm going crazy posts that makes most of the moms go 'oof at least mine doesn't do this!' 😶 My 1 yr old has developed the habit of rocking back and forth in his bed. This often leads to head banging. The daytime naps are fine he rocks at the beginning I pull him to the end of the bed and he falls asleep. He has 2 naps both lasting between 1 and 2 hours. His bedtime is between 7pm and 7:30pm. He drinks a bottle (180ml/5) does the rocking but falls asleep in about 15 min. The real horror show starts between 12pm and 1 am. He starts rocking with this rythmic humming/moaning noise you just can't ignore. And it lasts sooo long he just doesn't seem to really fall asleep anymore. He sleeps in our room and this has been keeping us up for 3 wks know and eventually I just cave and let him sleep with us (and the rocking and noise stops for most of his sleep). We've never really let him co-sleep before so it's not that he is used to that. He was quite a good night time sleeper before. Didn't need rocking by us to fall asleep just woke up a few times at night and would fall back after I found his pacifier for him. Please does someone have any advice? I'm working as a teacher from home during this Corona madness and I can handle tired but this is mind numbing exhausting. Anyone? Also I love my kid he's the best.