If your points aren't triggering, most of the time it's not because of the app, but because of a weak GPS signal. A number of things can block the line of sight of GPS satellites and cause a weak GPS signal and location issues. Narrow streets, walls, vehicle roofs, tall buildings, and mountains especially, are all examples of obstructions that can affect the GPS signal. The rule of thumb is that the GPS signal is most optimal under a clear sky, so if you can't see the sky then you'll most likely have a weak GPS signal.
Another aspect to consider is the fact that the maps are made in the CMS using Google Maps, and sometimes, the satellite maps are off by some meters.
We recommend a minimum of 15-meter radius, but sometimes 25 or more is necessary to activate a point. As a game admin, you can change the triggering radius.