@pelicanos If you were playing it across reset (ie had started that section before reset and then completed it after) the daily tasks can’t handle that and consider it to be from the previous day.
It’s been like it with events all this season - if you haven’t completed all your tasks on one quest before reset, then don’t try to squeeze it in before the cut-off otherwise you will likely lose both days.
You will still complete all requirements of the event easily - it’s a terrible event, but has so much event currency available that you could probably stop now and still claim all the rewards (I have something like 5000 points built up - it’s weird)