Citra cheat support is not 100% yet, some cheats not working or crashing is expected. check if your cheat(s) require that an specific game update be installed. also try other cheats.
but im play with the english traduction and some thext appears in japanese wen i apply the update. if you only need a cheat for a short time uninstall the update after.
google is your friend . i cant refer you. but i can refer you from the english patch forum , inside this are the instructions (need a 3ds). read the text slowly and you will find the solution, trust me:
I have read every page in your link, Ludovicus, and couldn’t find anything about modding/cheating/hacking in DQM J3, granted I did start skimming after the first dozen pages or so. It’s possible I read something wrong as well, given that I am not using my 3DS and am just using my computer to play (maybe that’s the problem?).