On the basis,, for marathon, you don't need to have qsl. The qso is enough.
But you may be right:
I do not have confirmation of ZD8, 3A, XV (and so on) for year 2020 qso.
On the other side, as I wrote, I worked ZD8SC, and after the qso, JTalert continue to report as "new marathon" which is not true as qso is already made with that station on same bande/mode...
This is same for any others
It sounds that, at a certain point (when, how, why?), JTAlert is not updating the statistic for Marathon.
Tell me which info you need. Thanks
73 - P@t