WCF service working but wsdl file not opening in only in PROD

Question

I have followed multiple questions here on stack over flow which suggest httpsGetEnabled in web.config and adding ServiceContract in code. But none of them are helping me.

My issue is only for my PROD environment. For QA enviornment I'm able to browse wsdl file.

Note : For PROD, other systems are able to consume my service and able to transfer data but I'm unable to browse wsdl file.

Tech Stack : It's .NET Framework 4.7 hosted on IIS 10.0.14393.0

Posting both QA and PROD config files.

 <?xml version="1.0"?>
<configuration>
  <appSettings>
    <add key="DevMode" value="QA" />
  </appSettings>
  <connectionStrings>
    <!-- My con string here -->
  </connectionStrings>
    <system.web>
    <compilation targetFramework="4.7" />
    <pages controlRenderingCompatibilityVersion="4.0" />
  </system.web>
  <system.serviceModel>
    <bindings>
      <basicHttpBinding>
        <binding closeTimeout="00:10:00" openTimeout="00:10:00" receiveTimeout="00:10:00" sendTimeout="00:10:00" maxReceivedMessageSize="2147483647" maxBufferSize="2147483647" maxBufferPoolSize="2147483647">
          <readerQuotas maxDepth="2000000" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxStringContentLength="2147483647" maxNameTableCharCount="2147483647" />
        </binding>
      </basicHttpBinding>
    </bindings>
    <behaviors>
      <serviceBehaviors>
        <behavior name="">
          <serviceMetadata httpsGetEnabled="true" />
          <serviceDebug includeExceptionDetailInFaults="true" />
          <dataContractSerializer maxItemsInObjectGraph="200000000" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
    <diagnostics wmiProviderEnabled="true">
      <messageLogging logEntireMessage="true" logMalformedMessages="true" logMessagesAtServiceLevel="true" logMessagesAtTransportLevel="true" maxMessagesToLog="3000" />
    </diagnostics>
  </system.serviceModel>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true" />
  </system.webServer>
  <system.diagnostics>
    <sources>
      <source name="System.ServiceModel" switchValue="Information, ActivityTracing" propagateActivity="true">
        <listeners>
          <add name="xml" />
        </listeners>
      </source>
      <source name="System.ServiceModel.MessageLogging">
        <listeners>
          <add name="xml" />
        </listeners>
      </source>
      <source name="myUserTraceSource" switchValue="Information, ActivityTracing">
        <listeners>
          <add name="xml" />
        </listeners>
      </source>
    </sources>
    <sharedListeners>
      <add name="xml" type="System.Diagnostics.XmlWriterTraceListener" initializeData="C:\logs\Traces.svclog" />
    </sharedListeners>
  </system.diagnostics>
</configuration>

PROD

<?xml version="1.0"?>
<configuration>
  <appSettings>
    <add key="DevMode" value="PROD" />
  </appSettings>
  <connectionStrings>
   <!-- My con string here -->
  </connectionStrings>
  <system.web>
    <compilation targetFramework="4.7" />
    <pages controlRenderingCompatibilityVersion="4.0" />
  </system.web>
  <system.serviceModel>
    <bindings>
      <basicHttpBinding>
        <binding closeTimeout="00:10:00" openTimeout="00:10:00" receiveTimeout="00:10:00" sendTimeout="00:10:00" maxReceivedMessageSize="2147483647" maxBufferSize="2147483647" maxBufferPoolSize="2147483647">
          <readerQuotas maxDepth="2000000" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxStringContentLength="2147483647" maxNameTableCharCount="2147483647" />
        </binding>
      </basicHttpBinding>
    </bindings>
    <behaviors>
      <serviceBehaviors>
        <behavior name="">
          <serviceMetadata httpsGetEnabled="true" />
          <serviceDebug includeExceptionDetailInFaults="true" />
          <dataContractSerializer maxItemsInObjectGraph="200000000" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
    <diagnostics wmiProviderEnabled="true">
      <messageLogging logEntireMessage="true" logMalformedMessages="true" logMessagesAtServiceLevel="true" logMessagesAtTransportLevel="true" maxMessagesToLog="3000" />
    </diagnostics>
  </system.serviceModel>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true" />
  </system.webServer>
  <system.diagnostics>
    <sources>
      <source name="System.ServiceModel" switchValue="Information, ActivityTracing" propagateActivity="true">
        <listeners>
          <add name="xml" />
        </listeners>
      </source>
      <source name="System.ServiceModel.MessageLogging">
        <listeners>
          <add name="xml" />
        </listeners>
      </source>
      <source name="myUserTraceSource" switchValue="Information, ActivityTracing">
        <listeners>
          <add name="xml" />
        </listeners>
      </source>
    </sources>
    <sharedListeners>
      <add name="xml" type="System.Diagnostics.XmlWriterTraceListener" initializeData="C:\logs\Traces.svclog" />
    </sharedListeners>
  </system.diagnostics>
</configuration>