Zip Code Search not working?

Problem: my zip code Advanced Search field doesn’t display any results.

Notes:
– I CSV-imported my listings and I’ve included the following fields:
map-address3, map-city, map-country, map-lat, map-log, map-state, map-zip, map_location
– My listing pages correctly show the address on the Google map
– My City search (Advanced Search) works correctly
– My Custom Field (General Settings > Advanced Search) shows the following:
– Search Field : map-zip
– Field Type : text
– Data Stored As : text
– Returned Values Must : equal search query

Any ideas? Thanks!