I have just tested the plugin, it still works fine, even with http (no https switch in the code). Why it does not work in your case I do not know, but OSM is very sensitive to wrong data input, you have to be careful about region, city, if anything is wrong, or if it contain a keyword it doesn't like (e.g. "some region" or "some city"), it will code 0.00/0.00 for lat/lon coordinates. Google Maps API is far more resilient to input errors and interpretations, that's why it's the best and without real competition atm.