if they were full of bees and brood 3 weeks ago and you've only given them one super i expect they are either crowded or have swarmed. we are in what i would say is the second half of the peak flow in my area. i hived a swarm in a deep with one frame of brood and 9 of foundation last wednesday evening and saturday it was almost completely drawn out. i added a medium of foundation sunday and expect to give them another this afternoon. in another week i may add a second deep of foundation depending on the flow and how much coverage the bees have (it was a big swarm). things happen really fast when the flow is on.
you need to see if they have backfilled the brood chamber, if there are queen cells or old queen cells that have been cut down, and you need to see if there are any eggs/open brood. i'm pretty sure you'll need to super them again. i don't know how the flow is in central florida but i would think it starts earlier and is much longer and better than central georgia/alabama.