بسم الله الرحمن الرحيم
Wiping the neck is a mistake and considered by some scholars to be an innovation, because of it not being a firmly established practice of the Prophet -sallahu alayhi wa salaam. On the contrary extremely weak narratives (supporting the action) were reported, and even mentioned by some scholars (as proof for the legitimacy of such), however (the ruling of) the narratives being unauthentic was hidden from them. For this reason it is not legislated to wipe the neck and it is necessary to be aware of this in order to safeguard the legislation from any additions.
Translated by Najeeb Al Anjelesi
Source: المنظار في كثير من الأخطاء الشائعة