Bobbinghead baby

My baby latches well and in the beginning of the feed he just quietly drinks his milk. But after a while he starts to get squirmish and starts bobbing his head and latching off all the timeI don’t know why, first I thought it for for 💩 purposes because he often farts or poops.. now I dont know anymore... he gets agitated and swings his head and body.. and if I try to burp him he cries and wants to relatch... maybe because de flow of milk is lower? Anybody? He is 8 weeks and EBF, doesn’t have nipple confusion