Central FL water is just high in sulfur. It is not always exactly the same---even at the same resort/in the same location, some years seems better and others worse. That could be more to do with how accurate my ability to smell is at the time!
I keep a slimline brita pitcher in my Owner's Locker. It's one of the few things in there that I use every trip.
The soda fountains in the parks and resorts are filtered, and they all have water dispensers, so that's another source of less-sulfury water.