No, mine does the same thing - except it leaks forward of the cooler, into the storage area.

I have talked to the local cover guy, and asked him to add to my cover, some material that would wrap around the tower leg,
about 8-10 high -- velcro/zipper, and tight at the top to close this hole. He suggested it would be easy, just cost some $$.

If you know what a "gaiter" is that someone cross country skiing or snowshoeing ... this is the concept in my mind. I have seen
covers with this built in for the tower. Something like this that is either attached to your cover, or would be "over" your cover - and
go over the area you're talking about? (for some reason, I can't get the image to work -- look here for a picture of a gaiter)