[twindman]

With a 2018 model, I wouldn't think the problem is in the seal. You may need to adjust the locking mechanism. My old trailer (maybe new one too) had a slotted thing that you could move in or out a bit to cause the bottom of the door to close tighter. Also, I seem to remember there is maybe a drain hole in the bottom of the opening that can plug up but I may be off on this. If not off, the water runs to the bottom and works its way inside instead of out. Try using a hose sprayer and hit the door around the edges hard and see if this causes the leak and track down where it is getting in.