very carefully look along the seam of the tub just above where the metal bends out for the heater hole the metal tubs are prone to getting swiped by the inner drum at this spot and crack it easily gets mistaken as the heater leaking
I had one a couple of years ago and after a lot of head scratching it turned out that the tub WAS leaking where the metal was folded at the flange. magnifying glass and a light I’m afraid.