You're talking about the 2 tall windows in the hall? Silly question, but the windows are clesed, right? When we bought our 37QDB, we were camping during a rain shower, wife walked around & check all the windows to see if it was raining in. An hour later, I walked to the bathroom & the floor was soaked under those windows. While it wasn't raining in, the rainwater rolled down the side of the coach, dripping onto the window sill & splashing inside. My solution was to install a strip of EZ Gutter to the top of those windows.
Make sure the drains are clear & the window is seated tightly down.
You may want to search www.tiffinrvnetwork.com
to see if anyone else had a similar issue.