My DJ Phantom 4 Pro going back to DJI GPS / COMPRESS Issues. If you can see I have two Phantom 4 Pro on this photo. The one of the right is going back.. you can see it has Compress issues
If you mean compass issues, not compress issues, then the first thing is to take it outside, it is not unusual to get compass issues inside the house. Same applies to the GPS, the GPS receiver does not receive well indoors either.