Hi arashmaz,
I tried that. And if I change the style of the "normal" state in button 1, I can indeed apply this change (for example a new color) to all the buttons with style "Bob".
But if I add a new state to button 1 - a state I call "test" - then there's no option to "save changes to style" it seems since I haven't so much changed the style as I've just added a new state.
Because you talked about 'buttons' I supposed that you were pointing to the InBuilt States: Normal, Rollover and Down. The situation with styles is a bit confusing IMO concerning states. You cannot define states in the Object Style Manager, as was the case for buttons in Captivate 8. Since Captivate 9 you have to define states in the Object State panel, for custom states as well as for InBuilt states. Part of the InBuilt states are really embedded in the style: that is the case for the whole state for Image buttons, for the Fill/Stroke for the other types and for shape buttons. The labels on buttons (text, system and shape) are not part of the style. The exception are the image buttons because you need to put the text in the images. If you are adding objects in InBuilt states, they wil not be part of the style. Same for Custom states: they are not part of the style. I have issues with this confusing setup. It would be much easier, I believe, if everything that was saved in an object style could be edited and changed IN the Object Style Manager.
The 'three lines' menu button, also called the hamburger or the hotdog button, has some possibilities to save changes to an existing style, to create a new style, to apply a style to objects with another default style (provided you didn't override it, which causes that + sign to appear).
To conclude this probably confusing answer: the work flow I suggested with object styles, will work only for those features that are saved in an object style (there is no real explanation in the Help AFAIK). Now I understand from your last answer (sorry) that you are talking about a state that is not InBuilt, but custom. In that case, you cannot change that state for all buttons at once. Only way is to duplicate buttons. My apologies, maybe I have to write a blog post about Object styles, and its manager. I have heard several trainers proclaiming that they never use the OSM.