Most often , I am seldom very comfortable disputing issues of this kind, principally because it avails little spiritual edification!

Why? Appellations and segregation into kinds and groups are human means to natural, not spiritual ends.

The term , 'Protestant', generally refers to the primary splinter groups from the considered first official Catholic Church due to fundamental doctrinial disagreement, like method of water baptism!It is in this light they are seen as Protestants as they protested what they consider not ideal.

Naturally, whatever is extremely homogeneous does not endure. It is therefore expected that the Church must be heterogeneous as different body parts, yet leveraging for a common goal of the one body.

I think the several Churches Jesus addressed in the book of Revelation is a pointer to this reality!!

Indeed , there are no protestant Churches, but for historical reference there are; the Baptist inclusive.