Reminders not working

Since I upgraded to iOS 10, when I have entered new Reminders in my iPhone 6 with dates/times to ring a reminder, as soon as I entered the date/time to ring and save the Reminder, the date/time disappear from the Reminder. I can save the Reminders and the text of them is fine, it's the date/time that resets as though I never even had a date/time for that reminder.

Thoughts?