Additional Eligibility | Able to Save blank data if Enrolled In sub Plan is not available

Environent: Stage
Company: MBF
Sub Plans not available
Pages: Rates, Add/Change Plan Design etc.All the pages where additional eligibility are available

Steps:

Rates > Additional Eligibility Criteria > AND > Enrolled In Sub Plan > equal to > No sub plans available in drop down > + > Save

Ideally, if drop down is blank it should not be able to Add or Save the criteria. If Text field is there it is accepted but under drop down it should not allow.

Screen capture for the same is attached with jira.