Button from Base Layer SHowing up On Other Layers EVen though Hidden?

Hover, Selected, and Visited are reliable. They may break if they are misused. The worst results and the most frequent abuse of the built-in states is to create your own trigger to get them to perform their built-in action. Deleting those triggers restores the reliability of the states. Probably the second biggest problem is making the objects part of a group, which can frequently break the states. A cause of Selected state not working is to incorrectly, or not configure a button set. Visited frequently doesn't work as expected if you leave its slide and later return to it. A frequent cause of this is to incorrectly set the the Revisit property. Choosing  Used properly, the built-in states are very reliable. The main impetus for creating custom states is needing functions beyond their scope.

If a slide is set to saved state on revisit. and a layer is open on leaving, it will still be open on returning. To avoid this, hide the layer before jumping to the succeeding slide.

If it were mine, I would replace the custom states with the built-in ones, and delete the triggers that refer to them. Everything you want is well within the scope of the built-in actions.

In regard to revisiting the slide from another, when you revisit a slide, the timeline restarts, whether you have it set to Resume, or Reset. Therefore, the Next button is hidden, even if all the rectangles have been visited. The solution is, indeed variables. States can become confused, especially if you have it set to Automatically decide.

 See the attached sample.