DIAGNOSIS Residual moisture and detergent in hidden areas—under the agitator, inside the fabric softener dispenser, and the door seal—are breeding mold.
FIX Run a cleaning cycle with hot water and two cups of bleach, not detergent. Then, manually scrub the detergent dispenser drawer and the area under the removable agitator cap with a bleach solution. Leave the lid open after every wash to dry.
IF THAT DIDN'T WORK Check the drain pump filter. A clog there can hold stagnant, smelly water. Clean it out as described in the drain problem fix.
HEADS UP Using too much detergent or fabric softener creates a sticky residue that mold loves. Cut your detergent amount in half.