Recently I've had a bug both with the android app and website that is very, very annoying. I can't change the date of any recurring tasks. So, let's say I have a task to water my plants every two weeks. It used to be that if I didn't wind up watering them that day, on the next day I could highlight the task and change the date to "due today," complete the task, and it would update accordingly, showing as due two weeks in the future plus one day. Now when I try and highlight a task and change the date to today it shows as being due today for a split second and then immediately changes to its next recurring date, as if I had completed it, but I haven't. Marking the task as complete at this point puts it two recurring dates ahead instead of one.
So, just to try and clarify the chain of events.
Recurring task for watering plants every two weeks was not completed yesterday, and is overdue.
I add the task to my day and mark is as due today, and the date shows as being due two weeks from now.
Marking it as completed at this point shows it as being due four weeks from now.