Mystery Dungeon: Shiren the Wanderer - Cheat does not work

The cheats worked in the past (infinite health and fullness), but just recently, I've found myself getting instantly killed by the stronger monsters, even with these cheats enabled.

Can someone help me out here? I'm using an M3i Zero and the lastest cheat.db file (I've updated the file a few times).

 

It may be an unstable code. Try with a new save file (keep your old one) and see if it still works.

 

Already tried a new save - didn't work.

An older cheat file works though, so I think I'll be keeping that as backup on my flashcart.
Kinda stupid that future updates have the potential to be full of unstable cheats though.