There are two problems in this thread.
First, many, not all, of the Roman Catholic participants use the term ‘Protestant’ to include everything from a LCMS Lutheran to a non-denominational evangelical anabaptist. It’s like asking about ‘people.’
Second, many, not all, of the Roman Catholic participants keep hampering on the 1500 year old gap, as if that is a neutral premise in the debate. I can assure you all that none of the Lutherans here believe that there is such a gap, but see the Lutheran church in continuation with the Church of History. We can, of course, debate if that is an accurate estimation, but to keep bringing up the ‘1500 year old gap’ – as the starting point of such a discussion – is simply to beg the question.
It is also important to note that the term Lutheran was not coined by Lutherans themselves, and in many countries, in Germany, for instance, the preferred term is ‘evangelical’ (Ger. evangelische, not to be confused with the modern American use of that phrase) or ‘evangelical catholic.’