And also, no one is reporting the number of test iterations that are being used for each positive result. There are people with very low viral loads, who are not contagious, that test positive.

If you run a RT-PCT enough times, you can generate a match in many cases where someone has never had the virus. The inventor of the PCR (who passed away years ago) took great issue with the way PCR was being using incorrectly with HIV testing. Even today with HIV, PCR is often reported with a viral load number, so doctors can tell what amount of antiviral drugs are needed for patients, and to help identify long-term non-progressives (rare) who may not need drugs at all.

There is this person who had two genetically different COVID-19 strains (but presumably the same serotype, there's only one serotype of COVID-19 known) for the first and second infection, confirmed by whole genome sequencing: https://doi.org/10.1093/cid/ciaa1275