I'm still having issues with making localization work in production (after following guide)

I'm still having issues with making localization work in production (iOS). I've followed the instructions to the T in the guide. I have:

import 'moment';
import 'moment/locale/ja'

in my index.js file and the moment initialized in app.js and set everywhere in the app. I configured my localization object with the localization strings and I set the locale in the calendar strip component. It works perfectly in development, but when deployed the app crashes immediately. If I just leave it as english it works just fine. I'm not sure how much code I can show since this isn't shareable but I can do best I can if there's something specific you would like to see.

Any tips? I'd really like this in calendar in japanese to work in production. It looks great in development.