As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE SANDEL TAWS/RMI SHOWS SIGNIFICANT BEARING ERRORS ON HEADINGS GREATER THAN 350 DEGREES OR LESS THAN 0 DEGREE. THIS PROBLEM WAS DISCOVERED IN FLIGHT AND VALIDATED THROUGH GROUND TESTING OF NUMEROUS UNITS. PROBABLE CAUSE OF MALFUNCTION IS SOFTWARE. THE ST3400 TAWS/RMI IS NOT RECOMMENDED FOR NAVIGATION AT THIS TIME.