Due to how serverless functions work, you cannot guarantee that a cached version of your data is available. Serverless functions are short-lived, and can shut down at any time, purging any in-memory or filesystem cache. This will probably generate downloads for each serverless function invocation.
Solution: We suggest to download the translations in your CI/CD pipeline (via cli or via api) and package them with your serverless function.
Solution: Follow this guide and bundle the translations with your Next.js app.
You've integrated the locize CDN directly in to your mobile app.
Due to how mobile apps work, when fetching remote data (like your translations), they will not be cached, event if you define some caching in locize. Such a setup will probably generate downloads on each app start.
Solution: We suggest to download the translations when packaging your app (via cli or via api) and bundle them with your mobile app.
Alternatively, if you still want to have some sort of "live" fallback and you're using i18next with react-native, you may want to try the alternative caching with AsyncStorage.
Beside these reasons, you may want to make use of the caching possibility for general browser usage or other alternative caching approaches.