microsoft graph api sdk returns null user even when the user is there

I am trying to fetch a user from a tenant by email. It works when getting some users, but doesn't work when getting a particular user who happens to have a '+' in the email address. I am not sure if that character is the problem or if it's something else. The query below always returns null for that user. My question, is how do I figure out why it's returning null when the user is obviously there for that particular user? I checked Audit Logs in AD B2C tenant, but they only show logins or deletions. Where can I check what happened with the graph API call? Second question, why would it do this? The user is obviously there!

   public static GraphServiceClient GetGraphServiceClient()      {          var clientapp = ConfidentialClientApplicationBuilder              .Create(Globals.ClientId)              .WithTenantId(Globals.TenantId)              .WithClientSecret(Globals.ClientSecret)                              .Build();                ClientCredentialProvider authProvider = new ClientCredentialProvider(clientapp);                return new GraphServiceClient(authProvider);      }     public static async Task<User> GetADUserAsyncByEmail(string email)          {              var graphClient = GetGraphServiceClient();              try              {                  Logger.Log(LogLevel.Trace, $"Contacting AD tenant {Globals.Tenant} for user {email}.");                  var users = await graphClient.Users                              .Request()                              .Filter($"identities/any(c:c/issuerAssignedId eq '{email}' and c/issuer eq '{Globals.Tenant}')")                              .Select("displayName,id,userPrincipalName")                              .GetAsync();                  Logger.Log(LogLevel.Trace, $"Finished contacting AD tenant {Globals.Tenant} for user {email}.");                  var foundUser = users.FirstOrDefault();                  return foundUser;              }              catch (ServiceException ex)              {                  Logger.Log(LogLevel.Error, ex, $"Error Alert:Encountered an exception when trying to get AD User {email}.");                  return null;              }              catch (Exception ex)              {                  Logger.Log(LogLevel.Error, ex, $"Error Alert:Encountered an exception when trying to get AD User {email}.");                  return null;              }            }  

https://stackoverflow.com/questions/66978340/microsoft-graph-api-sdk-returns-null-user-even-when-the-user-is-there April 07, 2021 at 09:13AM