When rent is too low it speeds up the leasing.   

Idle money is the quickest path to low returns and does no good for anyone.

I was initially drawn in by the low fee, which has since fluctuated, but may still be the lowest out there.

Low vacancy rates, rising rents, and high tenant demand for more space/good school districts. 

Those are spray and pray techniques that don't fit with sellers right now because sellers/owners are sitting on a very low rate and don't want to move to go up 4-5 points on their rate.Listings aren't a start now thing as well.

I'm running your numbers and getting in the low 20% range.

Mortgage rates and PMLs are 8-12% plus points right now so the deal has to be a low enough entry. 

The lock-in effect of the period from 2016-2022 when interest rates were super low, causing owners with those low rates to not want to sell? 

The area has certain advantages like shelter from regulation risk (pretty much as low as anywhere in the country if you buy in the approved STR tourist zones) and long term security (people aren't going to stop going to Orlando anytime soon). 

Weigh the long-term benefits of the low mortgage rate you have versus selling and getting $500k from a sale exempt from capital gains tax.