Button states - not changing once visited

Im aware that this has been discussed to death so apologies in advance- but for the life of me I cannot fathom why it its not working.

Im hoping you great folks can point me in the right direction - or is it i am just missing something obvious.

1. I want to set-up a conditional state where the 'next' button (graphic) appears hidden until all options on the screen (menu) are selected where the user is then allowed to progress. Then appears once all buttons have been visited

2. I have set up the buttons/graphics so that they have a normal/ visited and selected stated.

3. Each button takes you to a branched (quiz) page that once you 'submit' automatically returns you to the first (menu) page - this works fine.

4. I have even created variables with true and false when timeline starts on each branched page (visited page)

5. On Preview (scene) when each button is selected ( goes to applicable page) and returns; the status of the buttons/graphics on the 'menu' page still shows as Normal except one (out of 4 buttons).

6. As the next' button is set-up to only be visible once all buttons have a 'visited' state the 'next' button does not appear.

Any ideas thoughts/ direction?

Just feels like i'm a going around in circles