English missing from APK?

Compiling my app with the beta AIR 16.0.0.283 sdk, the english language seems to missing from the compiled APK.

I have the supportedLanguages tag in my manifest set to "<supportedLanguages>en de</supportedLanguages>". Odd enough the play developer console says that my apk supports only "standard" (german my case), "de" and "es" (!?).

Removing the tag adds all countries despite "en".

Going to "Optimizing tips" I get the hint, that I have added english translations (en-gb, en-us) to the store entry but not to the apk.

I am located in germany if this is relevant.

Any idea?