My kids did/do similar. There seem to be quite a few things they do at Childcare but not home. I’m pretty sure it’s because the routine is so cemented there and there are so many other kids all doing the same (kind of peer pressure really!)
My daughter will even tell me about certain things “no I do that at day care not here”!

a lot of kid do that. they see others doing it? maybe help with preparation?

My daughter is the same, she will eat 2 helpings of the food at school but not at home. I think they know they will not get anything else at school so they eat what they are given. My daughter will complain at home (till she gets what she wants, most times)

maybe he is copying the other kids

The different structure in the environment. The tricks they use at home and the attention they get would be different to what they experience at child care.

Maybe he saw all his friends ate it and he did the same too.

There are a variety of reasons as to why this happens. The main ones for your child are peer interaction ie seeing all your friends eating & enjoying the food as well as the ECE’s encouraging the children to at least taste the food before offering an alternative. Why not ask your centre cook for some recipes. Im sure they would be delighted to share.

Totally agree, maybe they don’t like it but it is something all the other kids are doing and the only thing going.

He knows he wont be offered anything else at childcare and the other kids are eating it, while at home he has more choices

I totally agree, maybe tell your child your child that the other children at daycare are eating it too.

maybe he is seeing the other children eating it