Well, a major disagreement. We can still discuss how and why we disagree case by case. Those 27 New Testament books in and of themselves are Apostolic. And are solely the verbal plenary God breathed written word of God given to God's church along with the Old Testament 39 books.
The Christianity has never been just a text book without a teacher.
The Catholic Church determined and assembled the Bible from its own tradition and Liturgy. It was the authority of the Catholic Church that told us what books were God breathed in the first place. And maintained the Apostolic interpretation of scripture.
That is why these new human founded traditions of men in Protestantism have no authority to tell anyone what scripture means, they had nothing to do with the Bible. They only wrongfully interpret scripture, cause ignorance and a loss of souls through that ignorance.
You say that there is perhaps only dozens of interpretive traditions in “Bible alone “Protestantism, I disagree, but let’s grant you that. Which of these traditions teaches the truth of scripture, and why is that interpretive tradition of more authority than the others?
The fact is none of these human founded interpretive traditions has any more authority than the others, and none of them had anything to do with determining or authenticating the Canon of Scripture.
Only the Catholic Church did that, and only the Catholic Church has the authority to interpret the meaning of its book.