there is a body seam at the front fender that leaks

I had this exact problem. Check what Junior said.

here is what I have seen personally

roof rack leaks, light bar leaks, sunroof drain leaks
where the fender attaches to the body leaks.
but they never do it until we touch the glass lol.
Good luck

ALWAYS check the front carpet before you start. If it’s wet make sure the customer signs off. That will help avoid the “you touched it last syndrome “

I have the cowl apart, do not find what you are talking about. Can you post a pic. ?