There are some Roman Catholics who deny this. They claim they don’t have to be subject to their pope in defiance of Roman Catholic dogma on this issue.
Read this and this (scroll down to Article V) ... carefully.
Note that both of them agree that obedience is not owed to human authorities who command one to sin, nor is obedience owed outside that authority's lawful sphere of authority. Note further that this would have been thoroughly familiar to Boniface VIII when he wrote Unam Sanctam, which quotes extensively from Aquinas.
Well, you see this is a matter of interpretation, and thus what manner of assent is required, as well as what the mannerr of assent itself all requires.
Reading what RCs say in forums, once can see that some assert that only infallible teaching is binding, though they disagree on what all these consist of, and which teachings in the CCC express them.
Some hold that infallible teachings include all of encyclicals, and some also include bulls, and others hold it only pertains to formal papal and conciliar decrees on faith and morals to all "The Church."
Others hold that only actual formal express definitions within decree to the church universal are covered by the infallibility clock, and not reasons/arguments for it (which is correct as per RC theology).
Still others hold that basically all public papal teaching requires assent (which is what so many popes expressed , but whether these statements were binding or not is part of the same problem), which usually requires them to be sedevacantist.
Still others hold that a second class (and third out of 4) of papal and magisterial teaching exists which require assent, while some (at least) reject social encyclicals as binding.
Then there can be another class of magisterial teaching and its manner of assent.
Then there are disagreements on what manner of assent requires. Some hold that "religious assent" does not disallow public expressions of disagreement.
Without further details, this led one exasperated poster on a RC forum to lament,
rrr1213: Boy. No disrespect intended…and I mean that honestly…but my head spins trying to comprehend the various classifications of Catholic teaching and the respective degrees of certainty attached thereto. I suspect that the average Catholic doesn’t trouble himself with such questions, but as to those who do (and us poor Protestants who are trying to get a grip on Catholic teaching) it sounds like an almost impossible task.
But the solution (before Francis at least) he was given was just obey everything:
Well, the question pertained to theology. The Catholic faithful don’t need to know any of this stuff to be faithful Catholics, so you are confusing theology with praxis. Praxis is quite simple for faithful Catholics: give your religious assent of intellect and will to Catholic doctrine, whether it is infallible or not. That’s what our Dogmatic Constitution on the Church demands, that’s what the Code of Canon Laws demand, and that is what the Catechism itself demands. Heb 13:17 teaches us to “obey your leaders and submit to them.” This submission is not contingent upon inerrancy or infallibility. - https://forums.catholic.com/t/catechism-infallible/55096/31
For the alternative can result in what as one poster wryly stated,
The last time the church imposed its judgment in an authoritative manner on "areas of legitimate disagreement," the conservative Catholics became the Sedevacantists and the Society of St. Pius X, the moderate Catholics became the conservatives, the liberal Catholics became the moderates, and the folks who were excommunicated, silenced, refused Catholic burial, etc. became the liberals. The event that brought this shift was Vatican II; conservatives then couldn't handle having to actually obey the church on matters they were uncomfortable with, so they left. ” Nathan, http://www.ratzingerfanclub.com/blog/2005/05/fr-michael-orsi-on-different-levels-of.html