Check out the rubber ring ( or called door seal) to see if there is black mold build up inside the bottom rubble. $ Z+ C L' V5 c9 {& s; ?4 r) c( J' X+ N7 g0 A/ U; _% p {
If it does have mold and can not be wipe out, then you have to change out the whole seal.. I bought a new seal and changed out few weeks ago.