Leaking lear camper shell

I have a 2017 Sport Tacoma 4x4. It leaks toward the front when it rains. It does not matter weather the truck is moving or not. The Lear install dealer says it is a Toyota bed design and cannot be stopped. They sealed the corners but still leaks badly if not worse than before they "sealed" it. is anyone else having this issue?

 

Look at where front bed rail meet's side rails. there is a gap, that needs to be sealed. Had same problem on my last Tacoma with shell.

 

https://www.tacomaworld.com/threads/rubber-plugs-for-gaps-in-bed-rail-available-now.420884/

 

You will also need to create a flap on the back to divert water away from getting inside the bed. There are a few threads about this and pics in the other seaction of the forum under caps and canopies