No don’t do that (file a change of address). That will only screw up your residency in Florida! But within two weeks of sending the stimulus check, the IRS sends out a letter telling you where it went. Was that mail forwarded to you? YOu should have received it by now. And that lets you file form 3911– to report your check missing. There’s even a box you an check if your check was “undeliverable” at that address.
Here is a link to the form (which I hope will work) — or just search out the form at IRS.gov.
And if that doesn’t work, your CPA is correct that you can file for a credit next year when you do your 2020 taxes.