This has been happening for months in other countries. IIRC, it was at least one First World Asian nation.
Recovered patients who tested positive for COVID-19 likely not reinfected
More than 260 COVID-19 patients in South Korea tested positive for the coronavirus after having recovered, raising alarm that the virus might be capable of “reactivating” or infecting people more than once. But infectious disease experts now say both are unlikely.
https://www.livescience.com/coronavirus-reinfections-were-false-positives.html