Forum Discussion
The link I provided in my original reply goes to a post with a demo that explains how to control the NEXT button on interactive slides. That should help you program your slides to ensure the user views all the layers.
I noticed that you copied a Group/button to the associated layer, and hid the original on the base. Why? If you simply show the Group on the base, you'll have less objects to worry about.
I also noticed you used a trigger to change an object to Visited.
That's not needed. Visited is a built-in state, so it comes with built-in functionality. Here's more info: PRIMER: Take advantage of built-in states - Articulate Storyline Discussions - E-Learning Heroes
In addition, I strongly recommend that you give all objects (or, at least, all interactive objects) and layers meaningful names. Do that for variables, too, when you advance to using those. That will make programming and troubleshooting much easier.
Here are some more of my general tips: