Mine did that too, but not from window
Nick, I spent almost a week trying to find where mine was leaking from and was exactly like you describe. I found the source to be the lifeline gate rail mounting bolt. I had to completely remove the galley cabinet to remove and seal the handrail. In doing so, I had wood rot on the paneling and inside the cabinet countertop. I couldnt do much to fix the countertop other than cover it, but I ended up removing the back paneling and leaving the gelcoat exposed which i think looks better.