It is not a change.
It should therefore be no surprise that we take notice when it appears there is disunity among Catholics.
The difference is that you're not in full communion with all Protestants, while Catholics who disagree with each other are in full communion with one another. In other words, Protestantism is not one Church.
-A8
Apostolics are also not in communion. Besides, no one has ever said that there is "one Church of Protestantism". However, among Protestants who are also true believers, all of us belong to the "one true Church of God", the same as you. Some Catholics belong to this Church, and some do not. It is the same with Protestants.