We are using mdg:geolocation package in our app to get the phone location but for some reason the accuracy on iOS is really bad. It seems that mdg:geolocation is not able to get GPS coordinates but only unprecise network geolocation. However if the user opens iOS Maps and refreshes the current location then of course the location is much more precise with the same result in our app.
Is there any mdg:geolocation option that has to be set to ask for a maximum precision?
Are you on wifi when getting the location? For testing geolocation I suggest being on your SIM cards data. Also, look into the accuracy of the returned coordinates, you could be in a bad zone of the accuracy is high.