As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT FROM LIM TO CUZ THE AIRCRAFT RETURN TO LIM DUE TO ECAM WARNING MESSAGE NAV GPS 1 FAULTGPS 1. AT LIM STATION TRANSFERRED TO DMI PAGE 06571 ITEM 2 IAW MEL 34-58-01 CAT C AND RNP-AR OPERATION PROHIBITED. THE AIRCRAFT RETURN TO NORMAL OPERATION.