Google Maps API Request Denied

When adding a listing and setting the address my browser console reports:
This API project is not authorized to use this API. Please ensure this API is activated in the Google Developers Console.

If I set the address, the console message repeats, plus I get a popup:
Geocode was not successful for the following reason: REQUEST_DENIED

I used to get both of these just by loading the GD general settings screen. But that has cleared up since I changed (and reverted) some of the GD/maps settings that chose to filter types and the default type.

I have GD installed as tests on two other sites and they get the first console message when loading the add-listing screen. However when setting an address, the console reports [object]s with addresses and the map works, unlike on the production site which gets [] then REQUEST DENIED.

All sites are SSL everywhere and have been for a while.

Google Maps Javascript API enabled and configured according to this document:
https://wpgeodirectory.com/docs/add-google-api-key/

I have already gone through these tests:
Disabled all plugins except GD.
Generated a new key in the console.
Deleted the key and created a new one.
Unrestricted the key.
Deleted the project and created a new one with a new key.

Immediately after creating a new key, the browser console on PA reported that the key was expired. But after a few minutes it changed and has remained with the above message.

Currently the new API key is unrestricted and installed on all three sites mentioned.

Thanks for your help.
Cory