As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING AN ICE RECONNAISSANCE FLIGHT AND APPROXIMATELY 6 MINS AFTER RESETTING THE HEADING AS PER FMS-45 THE DG WOULD BE OFF APPROXIMATELY 28 DEGREES. ON MULTIPLE OCCASIONS THE DG HEADING WOULD BE OFF PRIOR TO THE 8 MIN RESET TIMEFRAME. (TC# 20190712009)