On 6 August 2021, an Airbus A319 experienced uncommanded loss of both Flight Directors and the Flight Mode Annunciator and disconnection of both autopilot and autothrust in the climb. After levelling at FL350, significant inertial reference position inconsistencies were observed. A precautionary PAN was declared and the flight was completed. Investigation found that the cause was a momentary abnormal vertical shock load transferred to Inertial Reference System equipment through an overextended nose gear shock absorber by a sharp jolt during takeoff caused by a runway patch repair. Sensitivity of the particular inertial reference system installed on the aircraft was noted.