Application did not clear the alert message after clearing date from Expiration Date field (Section -3) and click out side

Company - LONG

Server- LB

Pre-requisite -1. I9 form submitted by employee 2. Expiration Date - should not be mandetory

Step:-
1.Login to application using partner credential
2.Search employee
3.Navigate to I9 form
4.Section 3: Reverification and Rehires
5.Enter today's date as "Expiration Date (if any):"
6.Click out side/Save
7.Application prompt alert message
8.Now clear the date and click out side

Actual - Applciation did not clear the alert message

Expected- It should clear the alert message