I resurrected the old mx5 from the drawer, but after updating to flyme 6 the mback key stopped working, I replaced 3 keys and none of them worked, I think it is a software problem, I have deleted all the data, I am also went back to flyme 5 and 4 but nothing does not work anymore, my original was a china version with flyme a, but immediately I installed the flyme i just received, could it be that meizu blocked the keys to those who carried out this practice?