On first, it seems that the PSM disable right after I turn on the screen, it may work normally and turn off so quickly.On first, how did you check? Pls see FAQ #14 if you haven't yet.
On second, yes that depend on mobile carrier support. But you can use the game booster method instead.
On second, I have tried Game Booster method today, and the floating bar did not appear in Game Launcher when I play the game. I don't know why, I have tried clear cache and storage both Game Booster and Game Launcher apps, nothing change.
I don't want to implement factory reset