As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT#187, BOS-LAX. (ETOPS) 'APU AUTOSHUTDOWN THREE CONSECUTIVE TIME ( APU SYSTEM A321NEO ETOPS ) APU FAILED TO LIGHT ON MULTIPLE FLIGHT AND GRD ATTEMPTS. NO FLAME; CHECKED PER TSM 49-00-81-810-821-A. REMOVED AND REPLACED IGNITER PLUG. NO HELP PER MM 49-41-41. REMOVED AND REPLACED IGNITION UNIT PER MM 49-41-38. APU START & OPS NORMAL. MDDR 540925 CLEARED.'