So, just for the heck of it, I tried deleting that particular Catalog UI Policy, and then rebuilding it.  Lo and behold, that seemed to fix it!  I don't know if the record was corrupt or what.  I created it the EXACT same way. 

The only thing to note was that the original Policy was created on Jakarta, and we have since converted to London (where they added the "Clear the variable value" option on the Policy Actions, though I did not use that setting).

Thanks for helping me identify the problem record!