The teaching of the Church is that the pope is only infallible when defining doctrine. Anything other than this the faithful should seriously consider the popes decrees but if what he’s saying isn’t being defined nor is contrary to already accepted dogma then, no, a disagreement between one pope vs another is not a problem and a Catholic is not bound by any moral punishment if they were to accept or neglect the advice of the pope. Although I find it interesting that a non-Catholic would be upset to hear this since most protestants think Catholics are “Papal kookaid drinkers” who blindly follow whatever the pope says. Also it’s kind of hypocritical for Protestants to have their own flip-flop in practices but still believe you’re guided by the Holy Spirit. Really the only difference between Catholics and Protestants when it comes the Papacy and infallibility is Catholics believe it’s an office handed down by Christ to St. Peter and his successors. Protestants on the other hand believe themselves to be their own infallible pope and magisterium.