We're experiencing the same thing on our 2021 Freedom Express 192RBS. Took it back to the dealer a second time because "resealing the window" didn't fix it.
I'm not a RV expert under any circumstances but I think it's something other than the window. Like a roof or seam issue that lets water in and then it can't get out. I've noticed that once it reaches sill height it doesn't overflow. So that tells me the water is still coming in during rainy weather but is filling up some other location. My guess is the space under the window in front of the pass thru storage and behind the rock plate. I can see water dripping into the pass thru from the top.
Hoping Campers Inn and Forest River do the right thing and don't do a band aide fix without really figuring out what the issue or issues are.
2021 Freedom Express 192RBS
2020 F150 STX 4X4 w/Coyote V8
Centerline TS WDH