Buttons send user back to first slide

I would like to include the quiz after a few slides (actually as you do in your example). However, when doing so, whenever I press a check answer button (or other buttons), then the user is directed to the first slide... Is there any option to avoid this that I did not understand?

The simple example I am developing is in https://github.com/djourd1/slideReveal Is there any way to avoid this?

Damien