Resource resolution paths: a values-id folder produces config "id", the runtime asks for canonicalized "in", no match, fallback to default. A values-in folder produces config "in", which matches.
Android

Android never loads values-id — Indonesian resources must live in values-in

/

A res/values-id folder builds without warning, ships in the APK, and is never matched at runtime. Indonesian users silently get your default language.