Your shower pan probably has a white foam to give it slope, this foam of course has colapsed and the pan flexed enough to crack and that is probably where the leak is, I had that happen and the only correct fix is either replace the pan with a new one or dissasemble the wall enclosure and the shower pan then remove the white foam and fiber glass the tub and then use some wedges and plywood to redo the floor where the tub rests, also check the drain fittings, on mine they tried to tighten the plastic nut and cracked it, I replaced it with a rubber union and metal adjusting straps, any other fix might not work as long as the tub floor flexes along a wall.
navegator