Fortigate is not allowing subdomain

Hi Experts I am facing one issue while I am to open a particular website I am going to explain the complete scenario in points I need your help & suggestion to fix this issue.

1. While I am trying open website its working fine but when I am trying to open subdomain of that website firewall is not allowing the subdomain but when I am checking it on logs its not showing that firewall is blocking the subdomain everything is fine.

2. I added particular website and subdomain in URL filter but still same issue.

Can anyone help me on this?