As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING MIDFLIGHT ALL 3 LAVS FAILED TO FLUSH ALL SHOWED FULL TRIED TO DRAIN LAV WASTE TANK, NOTHING WOULDCOME OUT, VERIFIED VALVE DOES MOVE. SUSPECT CLOG CLEARED 3 LAVE TOILET WASTE TANK DRAIN LINE BLOCKAGE IN REF TO AMM 38-32-00-160-803. TOILETS ALL FLUSH AS REQUIRED. OK FOR SERVICE AT THIS TIME.