That could be caused by a lot of things though.

For example: I could get sick, spend 5 days fighting it off and then spend another 3 or 5 days trying to catch up on everything that went to heck while I was sick. Thing is, I might not have actually cleared the virus (100% purged it from my body). By doing all that work for 5 days, any renaining virus in my body could have the opportunity to start the process over again. Ie: I didn't get a new infection. Its the same one I originally started with but never fully got rid of.

Another would be false positives from bad tests, which was an issue. The test says you have it and are asymptomatic but you aren't actually sick. To a person who got a bad test but didn't know it, it would look like they "got it twice" when they do actually catch it.

Things like that have been happening. The first is most likely since this virus can still be in your system for 5 days (or more) after you feel better and stop showing symptoms. Add to that how this virus can start by being asymptomatic anywhere from 2-12 days (5 seeming to be the average) and it is totally understandable how someone could think, "this can't be the original infection I had 2 weeks ago. I must have gotten it again from somewhere else."