Custom Theme with Audio Problem

[raccoonsoupkid]

So I made a custom theme (following the "How to Make 3DS Custom Themes *2020 Updated*" tuto)

First of, the audio only plays on the left speaker. When I change the theme then go back to mine, the audio from both themes plays at the same time (mine is on the left speaker, the other theme on the right one). It only goes back to normal when I restart my 3DS

On shuffle mode, my custom theme has the default 3DS menu music

Do you have any idea where the problem come from + how to solve it?

Thanks

PS: i used an entire song for my custom theme's audio idk if it could be related (the file is under 3.3 mb)