I'm wondering about this for a very long time now. I've read all books of Bart D. Ehrman or Elaine Pagels about early Christianity and many more, but no word or connection was to be found about the sect of the Nazarenes although the connection seems so obvious. https://en.wikipedia.org/wiki/Nazarene_(sect)
Why is this? Is it because historians don't want Christianity to have emerged from some teaching which was early on rejected as a heresy? I'm aware this is a very controversial question, but I just can't understand why this connection is not made? Can you please tell me what I'm missing about this topic? Thank you very much in advance.
I can't speak to Ehrman or Pagels, but "Nazarene" the word, the label, and the sect are hardly unknown in biblical/early Church scholarship. As a word it just means 'of Nazareth,' hence the appellation Jesus the Nazarene. And hence the term that some contemporary used for followers of Jesus, 'followers of the Nazarene'/Nazoreans (Nazarenes).
Where you might be getting tripped up is that Nazorean will also later be the name of designated sect within Christianity, as well as a term applied to Christians by outsiders. However, what later writers like Augustine and Jerome refer to as the distinctive theological beliefs of the Nazoreans from "Christians" are not compatible with the picture of developing Christianity we already see in Paul's letters and in Acts of the Apostles. Specifically, a good portion of Acts concerns the release of Christ-followers from the law of Moses (f.ex. kosher), through the rivalry between Paul and Peter; the distinguishing features of Nazarenes-the-sect are supposed to involve continuing to follow Jewish law.
William Horbury's essay in Christians and Christianity in the Holy Land and M.C. de Boer's piece helpfully named "The Nazoreans" in Tolerance and Intolerance in Early Judaism and Christianity might be good places to look for more info, although Horbury takes issue with some of de Boer's side assertions.