I'm confused why they are being rude

I'm not sure if this is the appropriate forum but I have a coffee shop that I regularly go to. last week the barista - who I've seen around but have never really talked to - told me that I was very pretty and I said thanks and that was sort of the end of the convo (I took it as a compliment nothing more nothing less) but when I went to the coffee shop again today he was acting sort of rude? and mean? towards me. I'm a little confused as to why they could be acting like this. I feel a little offended tbh lol.