Parents and I are at a loss

So I got a newer baby (4m) about 3 weeks ago. He was doing pretty well getting adjusted. He would eat and nap okay, mostly he would only eat when I was the one to give him a bottle. But all of a sudden last Friday afternoon, he would drink an ounce then scream whenever the bottle was put near his mouth (not too hot at the time). This was definitely odd behavior so we informed mom and dad and figured the weekend would get it straightened out. Well now all week he will do that behavior for every single bottle everyday. He'll be hungry, drink about an ounce then slow to a stop while still being content. So we put him down for a few minutes to assist other children and come back to him to try his bottle again. He screams and jerks his head around like he's afraid of the bottle. Parents are obviously very concerned that this has gone on for so long now and they say he eats normal at home but all of a sudden at school is the issue. Dad even came in today during one of the bottles to try and he did the same thing with dad and he was alarmed. I even had my director try with him just to get another witness for it and he did the same thing. Anyone else deal with this before or have ideas?? We are worried.

Edited to add: we have tried multiple ways of holding him and still nothing is working