It could be the shorts. I have several pair and some are way more comfy than others. I have never worn panties under my shorts but that is the way that hubby said that I should. I don't think that I ever will. I don't seem to have any issues.

Could it be just the fact that you sit differently on the saddle between your hybrid and your road bike? I had a big issue going from a mountain bike to a road bike.

I agree with tulip though you need to do what is most comfy for you. I ride with some ladies that wear panties and they will never change. But the majority of us do not.