Attachment not attached in Outlook mail system in C# UWP

Hi, I am trying to attach a file in the Outlook mail system using C# UWP, but it's not working. It works fine in the old Mail app. Could you please help?

Code:

EmailMessage emailMessage = new EmailMessage(); 
StorageFile attachmentFile = await storageFolder.GetFileAsync("TXT_Files\\Purchase Status.txt");
 if (attachmentFile != null)
 {
     var stream = Windows.Storage.Streams.RandomAccessStreamReference.CreateFromFile(attachmentFile);
     var attachment = new Windows.ApplicationModel.Email.EmailAttachment(attachmentFile.Name, stream);
     emailMessage.Attachments.Add(attachment);
 }
await EmailManager.ShowComposeNewEmailAsync(emailMessage);