Switching languages when replying to activity sharing notifications

I'm trying to switch to another language when replying to these notifications with some funny humour, but the presented language list is not right. Both English (UK) and English (US) are listed, but then some of the installed languages are missing. Or even if they show up, I can not switch to them. I have tried this both with the mirroring iPhone and the custom setup.

Is there some trick to get this part work more reliably and consistently? What is the requirement for the extra languages to appear - and how to clean up that extra English there?

Thanks