M2 free port is B key and my new wifi adapter is M2 A & E key. Obviously, it does not work. I am looking for a M2 B key adapter. Some info: https://en.m.wikipedia.org/wiki/M.2
My surprise has been to find that I think is the reason that the internal WiFi adapter does not work. The antenna connector has been unsoldered. Unbelievable, go fuck welding.