Why do my recurring tasks keep deleting?

Even if I check off the tasks each weekday (I have them recurring on weekdays), they disappear from 'My Day', they still disappear and have to all be manually re-added from 'Tasks'. I tried setting the due date for a period in the future but that didn't work either.

How do I resolve this? I just want a simple way to have tasks reoccur every weekday under 'My Day' without having to reset it every time.

P.S. I am using this service through the to-do website and not through the calendar.

Thanks.