Baby Not Taking Bottles

Hi, my son is 6.5 months old. He’s gone between breast and bottle since he was two weeks old with no issues. I’m work full time so he has been taking 3 bottles at daycare since the end of August. The past week or so he has been eating like 8 oz at daycare when he was previously eating 18... He just chews on the bottle and lets it run out of his mouth. He has been nursing fine. I know he’s been teething for awhile (I can feel his bottom two teeth) but I don’t know how to get him to drink his bottles. Has anyone else experienced this?