Update to #3:
If I use Photon for the Geolocation Address Formatter, it does position the marker in roughly the correct place (as you point out, not as accurately as the Google Maps API). The initial view, though, is still at 0, 0 (off the coast of Africa). I changed to rendering with Leaflet, instead of Google Maps, and the initial viewport is still wrong.
I'm experiencing the same thing with a new installation, using an Address field. If I look at my browser's inspector, the only payload being sent to the Google Maps API is "csp_test=true", no address or other information.
The location you see in the map is Latitude 0, Longitude 0, so basically Maps is not getting the information it needs.
The module's installation information is:
Machine name: geolocation_google_maps
Version: 8.x-3.12
Requires: GeolocationFieldjQuery UIjQuery UI AutocompletejQuery UI Menu
Required by: Geolocation - Google Maps API - Demo (disabled)Geolocation - Google Places API (disabled)Geolocation - Google Static Maps (disabled)Geolocation - Google Static Maps - Demo (disabled)