Can I cause a Submit button to reveal another button in addition to its normal behavior?

I am very new to Captivate. I'm working on my 2nd project. It's a pretty simple project.

The internal customer wants several youtube videos where each video is followed by a few questions.

The requirements for the slides are:

• Video has no player controls (once started, it must complete).
• Questions are only Knowledge Check style questions (no scoring, ever).
• User must answer questions before continuing
• Reinforcing text is displayed based on selecting the right or wrong answer.
• After the reinforcing text is displayed, user can move forward to next slide (more questions or another video).
• Must be responsive

My results so far:

• Fluid boxes seem to be working for responsiveness.
• I have video part working (Next button appears at the end of the timeline).
• I used Knowledge Check slides to create the question slides.
• I have reinforcing text appearing correctly based on the answer, using the built-in Submit abilities (Correct answer and Failure Message) .
• I'm stuck after the Submit button. The default behavior is that the user is supposed to 'click anywhere or press y'. This works sometimes, sometimes it doesn't. If I click randomly, eventually it will move forward. Occasionally, the 'Y' will move forward.
• To get around the above inconsistency I thought maybe I'd reveal a 'Next' or 'Continue' button when the Submit is pressed. But I still want the Submit to do it's correct/incorrect behavior that is built-in. I can't find a way to alter the Submit button. Actions seem to be available to other buttons, but not the Submit button.

How do I enable another button based on the Sumit button being pressed. I can't find that anywhere in properties.

Am I missing something obvious?