Fluid Navigation Collection loses left side menu when clicking link on a fluid page

We are on PT8.56.04 and HCM Image 23 and are starting to use more fluid functionality. We are preparing to start an image update soon and have PUM image 27 installed for review. In the Virtual image, Fluid Home, Employee Self Service, I am looking at the Benefit Detail tile.  On the Benefit Summary, I am clicking on the 401K link and the page opens and the left side menu remains in place. In our current environment, I repeat these steps but the left side menu disappears.

I have run traces in both environments and see references to iscripts in the trace from our environment while I do not see these in the trace from the virtual image. I am newer to iscripts so not sure if this could be what's causing the menu to disappear. This is a delivered collection navigation.