There are 2 different points here. Biden is losing support according to the Suffolk University/USA Today poll, that's true, but not entirely to Trump, also keep in mind Cubans, particularly in Florida tend to favour "not Democrats". The overall poll, the SU/USA Today poll has Biden way ahead of Trump, but seemingly its Dem funded. Rep funded, has Trump ahead, Dem funded has Biden, non partisan has them even. So its best to take a wide view, but with a large amount of salt at this point.