SSRS String values not passed as parameters to other reports

I have a situation where I need to have string values passed to sub-reports in SSRS (coded with Visual Studio 2017 but deployed on a 2008 Report Server).  The oddity is that I am able to do it to one report if the Action item is is connected a bar on a bar graph, but the similar functionality fails when the action item used as a pseudo-hyperlink is connected to a text box.