We have been using HolyBro Pixhawk 4 mini’s and Pixhawk 4 FC’s for a while and found since using AC4 we get a lot of bad compass health issues.
Revert back to AC3 and the problem goes away.
With AC3 the craft flies fine in position hold and auto missions.
Slightly off topic but:
We have also noticed that AC4 is far less stable with the same hardware and settings as AC3.
Regards Peter King (ausi1972)