IDK what floopie means, but it sounds like a perjorative.
I知 strongly convinced that there are some (maybe more than some) people in Frum communities who are convinced they had COVID when they actually had something else. I was a part of that cohort, and am now convinced I did not have COVID.
Or you had it and antibodies dwindled.
Which does not necessarily mean you wouldn't be able to fight it again. (Remember seeing reports (link?) that body can store DNA of antibodies to reproduce quickly should the need arise.)
If you had it recently, they may not have built up enough to show in tests yet (many first hand stories of ppl having COVID (testing positive), 2 weeks after recovery testing negative for antibodies, and a month or more later testing positive for anti bodies)