Programmatically creating the AzureAD SAML SSO application (a non-gallery enterprise app) not getting updated by the Identifier (Entity ID) value

Question

• Using Microsoft Graph APIs I'm able to create an AAD SAML SSO application (a non-gallery application) but I notice Identifier (Entity ID) value is not getting populated in the AAD portal on the Edit popup screen, and interestingly the value is showing outside (under the "Basic SAML Configuration") (screenshot added).

• When I test this SAML configuration with my some Service provider tool, SSO fails and I had to come back to AAD portal and update this Entity ID value manually in the Edit screen, then SSO works. So I kind of notice it's because of the Entity ID is getting updated inconsistently.

• Programmatically my code looks as below, Please help with any inputs if I'm missing something to get this Entity Id value updated consistently.

    // Create Application
    Application app = new Application();
    app.displayName = "TestName";
    app.identifierUris = Arrays.asList("some uri");
    app.web = new WebApplication();
    app.web.redirectUris = Arrays.asList("https://testredirect.com");
    Application registeredApp = graphServiceClient.applications()
        .buildRequest()
        .post(app);
  
    // Create Service principal
    ServicePrincipal sp = new ServicePrincipal();
    sp.appId = registeredApp.appId;
    sp.preferredSingleSignOnMode = "saml";
    sp.tags = Arrays.asList("WindowsAzureActiveDirectoryCustomSingleSignOnApplication", "WindowsAzureActiveDirectoryIntegratedApp");
    ServicePrincipal createdServicePrincipal = graphServiceClient.servicePrincipals()
        .buildRequest()
        .post(sp);
  

AAD portal screenshot