I haven’t heard of anybody testing positive from lingering virus more than 8-12 weeks later. Or are you referring to people infected in this wave?
Im gonna post this that I wrote sy the end of June.
My entire family gets covid a week after purim. Mother, father, sister, brother and me. parents and sister test positive then, brother and i get symptoms. Shortly after Pesach my parents test positive for antibodies. few weeks later me and my brother test positive for antibodies. parents both test negative for virus around the same time. now more recently siblings and i get negative swab tests (1.5 to 2.5 weeks ago). in quick succession sister tests positive while brother and test negative. next sister test negative but brother comes back positive. then brother comes back negative but i come back positive!