Every time i try to change my kiai it says <Please select a file to upload> and <Your sound has been successfully uploaded>. I don't understand how that makes sense and when i test my kiai it didn't change. I have made sure it is a .wav file so i don't know what could be the problem. please help.

Is it 6 seconds long? Or is it longer?

Have you tried to dl lp yourself? Sometimes the game takes a bit to understand that you changed a sound.

Due to certain silly bug when you succeed your upload it says both

Do note that the sound played on the website won't necessarily change until you either clean your cache or wait a few days (this means the new sound is already there, but your browser still has the old one saved and plays it instead of downloading the sound again). Change of kiai ingame should be immediate (well, maybe give it a minute).