[zapzupnz]

I got stuck with this a few years ago. I live in New Zealand. My bank used iOS’ number pad keyboard to let me enter a deposit amount in its app.

When I switched my phone to French language but left the region and formatting as English (New Zealand), it was clear the app developers didn’t know the difference between language and locale because suddenly I couldn’t deposit amounts with a decimal point; they didn’t account for the fact ‘,’ would show up on the number pad rather than ‘.’.

It meant that they detected my phone’s language rather than locale. It used French’s locale settings for the decimal separator despite the fact I had specifically set my locale settings to remain in English (New Zealand).

I complained and it was later fixed to detect locale instead — but seriously, language vs locale, not rocket science.