Problem with GPS in form on iPhone i7 ios 12.1.4

Hi. On i7 ios 12.1.4 GPS form can’t get GPS information. Is there a know problem with forms on iPhone? Our form is here, you can test it: https://ee.kobotoolbox.org/x/#Ycal. Also, this help is outdated: http://support.kobotoolbox.org/collecting-data/collecting-gps-locations. It suggests using app “GPS status”. However, this app doesn’t work on IOS > 10.