Issue: The Undo feature cannot bring back a deleted element that contains a diagram.
When you delete an element and that element, or its child element, contains a diagram, then the undo feature will not be able to bring it back and the model will go into an unstable state and you will not be able to commit the model back to the server.
Note: This issue occurs when using Teamwork Cloud 19.0 Sp2 or Sp3.