J.C.
The same thing happened with our daughter... overnight, she decided she despised baths... no traumatic experience or anything like that to induce her behavior. (It was so much screaming that my husband and I would flip a coin... bath or dishes!!)
I don't have much advice or insight, sorry. We tried everything... nothing helped, unfortunately. We just kept smiling and using a calm tone and eventually, she started to like baths again.