Free Form Text Entry Quiz Question - Multiple Attempts

Hi all,

I'm trying to create an interactive assessment for data entry users at my organization. I'd like users to review a patient's face sheet and enter the ZIP code listed on it. 

I set up a text entry field for the patient ZIP code and made the slide a free form quiz question. I was able to get the question to work, but one of my co-workers suggested that we let users try again if they get the question wrong. 

I tried adjusting the triggers to show the Try Again layer in the event of an incorrect response, but when I do, the text entry field is no longer editable. 

Any thoughts on why this could be happening or what I could do to fix it? 

I've attached a copy of the file. I really appreciate any help anybody can offer.

Thank you!