I added the Google Maps JavaScript API to Geocoder and the Geommunity3 Maps configuration. Same result. Just to be clear... I'm using free Development API's, not production API's.
Also, there is a slightly newer CB build released. Same version#, new build#:
My version is 2.1.2+build.2017.06.20.19.28.55.3ab723c15
Latest version is 2.1.2+build.2017.06.23.22.16.38.2c6bbd64f
I'm not a CB subscriber, so I'm still using the c15 build.
I installed Joomla and databases from Akeeba Kickstart so if there was a problem on my local machine, I'm guessing it's on the server now.
Edit: Same result with Geocode API empty.
Edit: Within Geocoder, I temporarily toggled [when to]-Geocode, Debug, and Default map type. Working fine now with original settings as pictured above.