The WPA2-Enterprise authentication was configured in the policy.
The AP was configured as RADIUS server to communicate with the Active Directory.
The Domain Users and the Users in the Work Groups were successfully authenticated in Windows 10 and 8.1 without any issues; however, only the Work Group users were successfully authenticated in Windows 7, but the Domain Users were not able to authenticate.
Please note that this problem is only for the Windows 7 Domain Users.
I've gone through online KB articles that advises to manually add the network adapter and un-tick the server validation option.