[JKT]

A further update on this:

You can type the first half of the Post Code and it will work, but if you include the second half it will fail. Fwiw, the first half of a Post Code will tell you what borough your location is based in, but the second half pinpoints the actual building(s) within the borough. So it only helps to narrow down the search to an actual street and not the place within the street.