ZIP code not accepted if not focussing

Indeed the registration UI is missing something if one omits to put the cursor inside the zip-code textfield:

• use a registration form, put a zip code, forget the user type or to tick the agree (it works with social registration) or without)
• submit, you get an error that you did not answer all fields
• do not put the cursor in the zip code field (which displays the city) but answer the missing fields
• submit
• bug: zip code is not accepted because the JS-filled values are not filled.

Workaround: focus in the zip code field. This should not be needed.