Application did not prompt alert message for today's date for "Additional List A Document"

Company - LONG

Server- LB

Pre-requisite - I9 form submitted by employee

Step:-
1.Login to application using partner credential
2.Search employee
3.Navigate to I9 form
4.Select - Attest - A lawful permanent resident
5.In Section 2
6.Select List A any document
7.Select Additional List A - any document
8.Select Today's or previous date from date picker
9.It prompt alert message
10.Now just click inside the field and click out side

Actual- Applicationdid not prompt alert message

Expected - It should prompt alert message