change state of text box trigger isn't working

Very strange behavior! The problem isn't the top text box. It's whichever text box is associated with the icon that is clicked first. For example, if I decide to click the bottom icon first, that text box doesn't show, but the others do. 

That is what's politely called "unexpected behavior." I suggest you submit a case directly to the Articulate staff. You can do that here: https://access.articulate.com/support/contact