No Interval, changing interval type

I edited one of my schedules, but now the Interval option is missing from the schedule screen. See the attached pic. I suppose I could delete that schedule and create a new one so that I can create the Interval that I want, but it is frustrating that you have this bug. Please fix this.

Once a schedule is created with a certain interval type (day of week, odd/even, frequency) it can not be changed to another interval type. The easiest thing to do is create another schedule.