IFS 8 SP2 Login Issue: System.Net.WebException: The operation has timed out

Hello,

We are using IFS apps 8 SP2.

While login into application with IFSAPP getting below error.

Below are the information regarding our IFS environment.

1. IFS Application version- Apps8SP2 on windows.
2. LDAP configured (All end users mapped with AD are working fine and able to login in the application without any issue)
3. Facing ‘Operation time out’ issue with IFSAPP user only because it is automatically bypass the LDAP authentication and use database authentication.
4. Getting same error if we try to open the application from ifshome with ‘Ifs.Fnd.Explorer.exe’.

Ifs.Fnd.FndSystemException: Unexpected error while calling server method ClientApplication/IdentifyCurrentUser

   at Ifs.Fnd.AccessProvider.FndConnection.InvokeInternal(Object requestBody, Object responseBody, String intface, String operation, FndRequestContext requestContext, FndManualDecisionCollection decisions, Boolean forcedSync)
   at Ifs.Fnd.AccessProvider.FndConnection.InvokeInternal(String intface, String operation, Object requestBody, Object responseBody, FndRequestContext requestContext, Boolean forcedSync)
   at Ifs.Fnd.AccessProvider.Interactive.FndLoginDialog.AuthenticateCredentials(FndLoginCredentials loginCreds, Boolean isWIA) ---> System.Net.WebException: The operation has timed out
   at Ifs.Fnd.AccessProvider.FndConnection.HandleHttpStatusErrors(HttpWebResponse result, Exception innerException)
   at Ifs.Fnd.AccessProvider.FndConnection.GetResponseWithoutPersistencyHandler(String intface, String operation, FndRequestContext requestContext, FndManualDecisionCollection decisions, Byte[] requestHeaderBytes, Byte[] requestBodyBytes)
   at Ifs.Fnd.AccessProvider.FndConnection.GetResponse(String intface, String operation, FndRequestContext requestContext, FndManualDecisionCollection decisions, Byte[] requestHeaderBytes, Byte[] requestBodyBytes, FndApfAsyncInvoke asyncInvokeHandle)
   at Ifs.Fnd.AccessProvider.FndConnection.InvokeGetResponse(String intface, String operation, FndRequestContext requestContext, FndManualDecisionCollection decisions, Byte[] requestHeaderBytes, Byte[] requestBodyBytes, Boolean& abandoned, Boolean forcedSync)
   at Ifs.Fnd.AccessProvider.FndConnection.InvokeInternal(Object requestBody, Object responseBody, String intface, String operation, FndRequestContext requestContext, FndManualDecisionCollection decisions, Boolean forcedSync)
   --- End of inner exception stack trace ---

What could be the reason for this issue.