My rear window, which is also the emergency escape, is leaking. The window has been pulled and reset with butyl tape and sealant 2 times by two different Reputable RV repair shops.  One of them replaced the rubber around 2 sides of the center panel. Both times they have said the window and the seal looked fine but they reset it as a last ditch effort.  The window is 3 panes with the center one opening. The leak is directly below where the left and center panels meet ( when looking out. ). There is no water around the window or in the tracks. HELP!  Have any of you experienced this or have any suggestions?  TIA

Mary