We receive a complaint from a user that the compass heading in our paragliding app differs from the heading in Compass app (preinstalled on iOS). During our research, it was found that third-party apps show the wrong compass heading. We get the compass heading according to the documentation (https://developer.apple.com/documentation/corelocation/getting-heading-and-course-information#Get-the-current-heading): func locationManager(_ manager: CLLocationManager, didUpdateHeading heading: CLHeading) { magneticHeading = heading.magneticHeading trueHeading = heading.trueHeading } The video linked below shows our app and the third-party app getting the compass heading of 270 degrees, and Compass app (preinstalled) getting the compass heading of 30 degrees. https://drive.google.com/file/d/1HPMRWWq1E_bFYZVyCeqB2Fo-AfG4q9J7/view?usp=share_link This problem appears to the user unpredictably and the correct compass heading is shown by Compass app (preinstalled). He has iPhone 15 Pro Max and iOS 17.4.1. The presence of this problem is very critical as it can cause fatal accidents.