Help HN

Hi HN, I have a request, I know it's not stackoverflow, I checked but I haven't found a solution to our problem yet. :/ Basically we are a startup, started from scratch, and built a platform for tourism. We chose to work with xamarin (yeah I know bad choice). Here is how the app works : You see a map, with points to discover, and when you get near the point, there is a range setup to unlock a notification that gives you some information on the point of interest. Kind of a cultural and historic treasure hunt. Now we are hitting a wall as notifications on Ios get unlocked when you are very far from the point of interest. On android it works very well. If anyone has experience with this please help :)