I may have found a bug for the "no encounter" cheat, it works at first, like i could go through an entire cave without encountering anything, but if I go inside my bag, look at my party, or even look at the pokedex, the cheat gets disabled on it's own (it still shows that it's ON but i start encountering again, and i didn't even press START). After encountering something even though the cheat is ON, if i try to turn it OFF it crashes the game and the 3ds has to restart. It happens on both Sun and Moon.
I sorta got to workaround it and it was that after encountering something, I disable/enable another cheat to be able to disable the "no encounter" without crashing the 3ds, and then turn it back ON and then it works again. But the same thing happens if i go into the bag, party, or pokedex again after, which is that i start encountering again even though it says ON.
I'm on 11.4 N3DS, both Sun and Moon are on v1.2, and i'm using the v1.0.0 release of the SuMoCheatMenu.
EDIT: Going into a trainer battle also disables it.