CoreLocation returns asynchronous data that may not be synchronized with Japan Post's data

Hi I want to inquire about the data returned from CoreLocation update and whether it is accurate. I am attempting to retrieve the local address in Japan based on the postal code, and I have observed differences in the returned data.

When calling the information retrieval function with the postal code 3360042, the returned data is as follows: Locality: さいたま市 SubLocality: 南区

Corresponding to Japan Post:

https://www.post.japanpost.jp/cgi-zip/zipcode.php?pref=11&city=1111080&id=38748

the displayed information on the website includes "Locality + SubLocality".

When calling the information retrieval function with the postal code 1350064, the returned data is as follows: Locality: 江東区 SubLocality: 青海

Corresponding to Japan Post japan post:

https://www.post.japanpost.jp/cgi-zip/zipcode.php?pref=11&city=1111080&id=38748

the displayed information on the website only includes "Locality" not includes SubLocality. Is it possible that CoreLocation has been updated? The current data seems to deviate from the design of our application.

Please provide me with a solution to determine when to use "Locality + SubLocality" versus just "Locality" to obtain the local address.

Thank.