I am medium in everything jersey/jacket shaped, pro team or no.
I have two pairs of PT bibs, one medium, one large, the medium seems more generous in terms of fit than the large, which has eternally confused me.
I am currently in between sizes I think but I prefer the cut on PT stuff than classic/club although the new brevet jersey gilet combo is fucking amazing.
I'm not sure how people get so confused by the sizing.
Sizes are consistent. Cut varies by intended use.
Bibs are (obviously) a different box of cats.