No, there is no solid evidence of persistent infections. The few reports of repeat infections are highly likely to be caused by testing artifacts. The imperfect sensitivity and false-positive rate of the tests means you'll always see people who tested negative at one time, and positive at a later time.
As an RNA virus, it would be extremely difficult for SARS-COV-2 to establish persistence. I'm not aware of any known mechanism by which that could happen. It's been proposed that some COV's may have neurotropic capability [1] that might allow them to achieve latency, but it's just that -- a proposal.
