I am trying to consume the Google Reverse-Geocoding API using the following URL:
Setting this URL automatically creates "Latitude" and "Longitude" parameters in my REST Action. Pressing the TEST button after setting sample values works perfectly and returns the expected data.
However, when I try to call the REST service from my application, it returns ZERO_RESULTS. After much confusion, I finally logged the REST call data to find the longitude parameter had been dropped from the URL.
That is indeed a know issue and it's still in backlog to be fixed.
The workaround that you found is the recommended one.