How do i edit my 'button' settings/preferences captivate 17

Hi, I have created a flow chart in captivate17 and want people to be able to click on certain parts of that flowchart to gain further information. So i set the shape as a 'button'. The jumping to slides etc all works perfect, but the problem i have is (and i think it might be the 'state'?) is that when the user clicks on the button the text goes so large most of the text is not visibile in the shape anymore. I like the fact it turns a different colour when you interact with it but is there anyway i can keep the text from changing size? I have looked at the change 'state' and selected roll over etc but they all seem to have the same problem.  I have added some images below.  The first one shows what the shape looks like after you hover over it/click on it, the second image shows what it looks like before hand (you can see the text size has changed)