Just checked after the rain last night and the bladdy thing has leaked again! The leak is in pooling in the inside slider of the door.

Checked all around the outside and there is no other leak apart from the bit in this window sill. There's no leak coming in from around the frame itself so we are super confused

Anyone had a similar problem? How did you remedy it? The van is currently up on jacks so didn't know if this could be causing the problem. He obviously needs to be dry before we put anything back in/ flooring down...