As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMOKE IN COCKPIT / CABIN: WHITE HAZE DEVELOPED IN THE CABIN AFTER ENGINE SHUTDOWN WITH APU RUNNING AND APU BLEED AIR ON. THERE WAS NOT ODOR FROM THE HAZE. REMOVED AND REPLACED APU REF 680A MM 49-10-00 OPS AND LEAK CHECKS GOOD. NO SMOKE OR HAZE DURING RUNS