“Ahh, but אחר used to be עלישה בן אבוי׳ who we quote in פרקי אבות and went off the derech because he couldn’t keep the level he was on (פרגוד) and he taught ר מאיר before he went off”
Yes so what? Once he became a kofer and was acknowledged as such by everyone including himself, he was no longer a Rebbe, thus the halacha didn’t apply.”
What about the hundreds (probably thousands) of examples in shas and poskim where rabbanim do not hold like their predecessors and their own rabbanim, including the Rambam MANY times? Do you honestly think your understanding of the Rambam is even close to correct? You literally cannot hold different than your rebbe? I can read the Rambam too, but to apply such a superficial reading to this discussion, especially when the plain reading is already clearly not how our mesorah works (where there are differences in psak from rebbe to talmud), is pretty shocking.