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Hopefully the installation of a new window will address the leak issue..., especially if the root cause was a defective window assembly.
Depending on the particular OEM window manufacture and associated installation requirements, I've seen Jayco window installations (like mine) that utilize a rubber bulb seal which can be 'compromised' at time of installation resulting in a leak.
Utilizing Butyl putty tape IMO is a more effect RV window installation seal and is commonly used when replacing most types of RV windows.
2016 GM 2500HD 6.0L/4.10
2018 Jay Flight 24RBS
2002 GM 2500HD 6.0L/4:10 (retired)
2005 Jayco Eagle 278FBS (retired)
1999 Jayco Eagle 246FB (retired)
Reese HP Dual Cam (Strait-Line)