Address and postal code search missing

Edge 830 ASIA, software 4.10.

This unit comes preloaded with Asian maps. The option to search for address is missing.

So I copied an OSM local map into the Garmin folder. The option to search for address now appears, and it functions.

But there is still no way for me to search by postal code which is the fastest method to find an address.

Using my old eTrex touch with the exact same OSM map, I can see and search for postal codes under POI.

Anyone found a workaround for this problem?