[Solved] Azure app service with custom domain Error: An existing connection was forcibly closed by the remote host

We have an MVC5 application whch connects to azure database, it works in local but after deploying in azure app service which has a custom domain configued we get error as "An existing connection was forcibly closed by the remote host.".

Application works fine when deployed in an app service without custom domain name.

Please advise if any configuration needs to be done.