One can only hope you did not pressure wash around the window frame ...
I don't remember which company we used, but we ordered 3 different samples which all looked like what we needed, even matched the dimensions (we took out our rear window/frame and measured everything).
None of them fit properly. One was close but would bulge when going around the corner.
So we put the old seal back in and keep using silicone to fill any gaps.
A shocker: when we removed the seal, the window actually wanted to come right out! Wouldn't you believe it, the only thing that holds the window in the frame is the glue between the glass and the frame, and the rubber seal on top of it.
Needless to say we bought proper sealant, glued the window back in the frame and then the rubber seal on it, and into the frame.
Stopped at General RV a couple weeks ago, mechanic there said that pretty much every windows manufacturer used their own 'style' of seal, it would be better just to buy a new window, complete.
Good luck though! We have been using sealant to fill gaps for over a decade now, and so far had no leaks no more.