Sit can not be reached on Azure VM IIS

Hi,

My application is deployed on IIS on Azure VM. I got exception "This site can not be reached" when accessed from internet. I logged in the VM and browse application on localhost and it did not work. I restarted the VM and everything started working, application was accessible from internet and localhost inside VM. I am attaching the exception for your reference. What could be the possible reasons for this issue ?

Note: The VM is behind the firewall and can be accessed through VPN.

Thanks.