Hi, Elaine.
Thank you for reaching out!
Without looking at your .story file, the initial thought would be that this is related to the number of attempts allowed.
If you have more than one attempt, when the user chooses the incorrect one and submits, they have a chance to try again, but no message is given since you deleted the Try Again layer.
A simple fix would be to change the number of attempts to one.
If that's not the case, would you feel comfortable sharing your .story file here? I would be glad to take a look, and others in the community might be able to offer suggestions as well.
Let me know if this works!