Thank you for reporting this issue to us. Unfortunately Hong Kong is currently not available for a download.
We will try to fix this as soon as possible (~1 week). We will let you know once we fix the download for Hong Kong. Then you just need to update the map data of PocketEarth to be able to download Hong Kong.
Hi, We are happy to tell you that we could fix the download for Hong Kong. To update your map data please go to Settings > Data Cache > Check Now. Afterwards you can search for Hong Kong in the destination search / list and download Hong Kong for the offline usage.