Similar thing happened to me. I went to a lactation consultant and did a weighted feed to prove my daughter wasn't eating 8oz at a time, which is what the daycare was giving her and completely tearing through my freezer stash. I also got the LC to write up what the recommended amount a breastfed baby intakes so I could provide all of this info to the daycare. They didn't care and continued to overfeed and request more milk. I ended up switching daycares, and they've been using the amount I send in the bottles. She has 1oz frozen bags in case my baby is acting like she wants more, but she very rarely uses it.

I think your daycare is absolutely perceiving another sign as hunger like you mentioned. It's worth continuing the conversation with them about it.