PA could be using a different method (or keys are remapped when you enable in reboot menu). However it could be an error like Samsung devices have and you need to reboot for it to work (I imagine you've already tried this though)
// LG G3 (D855) // Stock // Stock //

S3(White) > M7(Red) > Note 3(Black) > Nexus 5(Black) > M8(Gunmetal) > LG G3 (Titan Grey)