@glutanimate Thanks for elaborating; that sounds like it would be saving after every note. I don’t think we supported undoing from the add screen, as there’s a history button you can use to access the recently added material.
@nakul1999 It sounds like you shouldn’t have lost more than 1 card when undoing. Have you tried searching for the cards in the browse screen? Can you reproduce the problem after disabling add-ons, and testing with the latest Anki version?