Problem
The fields for either a fixed expiry date or a duration disappear when you fill in the other field.
Possible cause
The form only allows one method for setting expiry at a time. If you enter a fixed expiry date, the duration fields are hidden, and vice versa. This is intentional.
Solution
Decide whether you want to use a fixed expiry date or a duration in months/days.
Clear the field you do not need — the other option will reappear.
If the problem persists, contact support and include details about:
Which expiry method you are trying to use.
When the issue occurred.