FYI there is a different and possibly more reliable solution to make different parts of a GH repeat and others not
inrepeatedgroupheader can be used to hide/show.
it returns TRUE or FALSE based on if the GH is the first instance of the GH(FALSE) or subsequent instances of that GH (TRUE).
It is also a tool to use to add verbiage onto the repeated GH.
For example
GH field format editor
common tab
display string formula use this to add a '(cont.)' to your header
currentfieldvalue + if inrepeatedgroupheader then ' (cont.)' else ''