Conditional region to hide/show subtotal not working when 4 subtotals used

BI Publisher Plug-in (v. 12.2.1.2.0) - for Microsoft Word 32-bit using "Standalone"

MS Office 365 ProPlus provides the MSWord version 2002 (Build 12527.21416 Click-to-Run)

Requirement was to allow user to optionally subtotal on fields (up to 4 maximum) get passed in via .xml data. They can be user choice between several fields. It's all working except for an extraneous unwanted subtotal line that displays when showing only 1 or 2 or 3 subtotals. Need help getting this across the finish line please. Details follow.

Generically named xml tags are used to identify which fields are desired to be grouped/subtotalled upon...if the generically named tag is populated with a field name then it should be subtalled... otherwise that xml tag is empty in the data then no subtotal is desired. The order of populating them is always GroupBy_FldName1, then GroupBy_FldName2, and so on up to a maximum of GroupBy_FldName4. Then corresponding xml tags pass the actual values to be grouped/subtotalled in the detail rows.