Tabbing in Knowledge Check

I have created a knowledge check slide that is exhibiting an interesting behavior when I am tabbing through the project. I have set the state of the "next" button to hidden when on the correct and incorrect results layers are shown, however I am still able to tab to the location where the "next" button is. Additionally, when in that location on the incorrect layer, if I press enter twice the slide advances to the next slide. It is my hope that the learner will be required to click "try again." I have attached a decontextualized file as an example. If anyone has any insight, I would greatly appreciate it. Thanks.