Not kawaii sounding enough at baito

I've been working half a year at this sushi chain. I use keigo and interact with all customers politely.

Last week a supervisor (someone who I dont normally meet) pointed out to me that because I was young, I should be able to make my voice more high-pitched and kawaii sounding.

I dont speak at a high pitch because it sounds gratingly annoying to myself, plus the exertion winds me. The supervisor herself maintains an anime girl manner of speaking ergo similar to an enthusiastic chipmunk.

I dont have a deep voice although I may have come across as tired when the supervisor heard me talk but I certainly was not being rude or grouchy.

I cant imagine someone telling me to speak in a high pitch in any country other than japan lmao. Just wanted to hear if anyone else has similar experiences/ what your thoughts are.

Edit: no I'm not japanese. The boss doesn't care about tone as long as I come off polite. (He's SEA like me) it's the japanese supervisor who's expecting a high shrill anime voice. And I'd like to think I wasn't sounding dead inside, just weak voiced perhaps. And I can understand how it's the same in customer service worldwide. Just feel that japan is on another level. Itll be a cold day in hell before i change anything when I'm only getting minimum wage tho XD