I grow cantaloupes in Florida but they...

If you’ve had an exceptional amount of rainfall during the ripening stage, this could cause the bland fruit. It also depends on which variety you’re growing. You should consult with your local extension office to see which varieties they recommend for your area. There are ones that can be very sweet, but also too susceptible to mildew or other disease. Some less sweet varieties have greater disease resistance, so you may have to experiment before getting just the right variety.