Since the graduation date was previously populated and disabled, there was no way for the user to clear the form before submitting. Added required to yup.
Updated logic surrounding isGraduatingBeforeCohortEndDate, this now disables the form before being submitted and prevents users from graduating a participant before the cohort has ended.
Bug Fix
isGraduatingBeforeCohortEndDate
, this now disables the form before being submitted and prevents users from graduating a participant before the cohort has ended.