When i change my kiai, it says it has uploaded, but it's still the same kiai. It also tells me to choose a fil when i already have, can someone help me with this please.

did you test it ingame

Actually, your kiai have changed
the first time i change the kiai, i tought the same thing like you i think the kiai cannot be changed, i really frustated, then i open toribash and play MultiPlayer, the kiai is worked, just test it in game, ignore the play button