Hi Keith,
You have your timeline with chapters and no end actions on chapters – only end action is on the timeline as a whole. Link your “Play All” button to this timeline and set the end action to return to the menu (select which button you want highlighted when it returns). If you have “10” chapters and “10” chapter buttons on the menu, then you will create “10” playlists. In each playlist you will add 1 chapter. Each chapter button on the menu will link to the respective playlist. Give each playlist an end action to return to the menu (select which button you want highlighted when it returns).
Hope this helps.
Ricky