"not set" appearing in Content Grouping reports despite being hard coded
When I go to the pages report in GA, and select one of my content groups as the primary dimension, I see a very (very) small percentage of page views to the "not set" group.
This would make sense if I didn't have a group applied to some of the pages, but the content group value is assigned to every page view in the GTM container using a constant value.
When exploring those pages appearing in "not set," there are generally only a couple of views to a given page that come back as "not set" while 99.9% of the rest of that page's views are correctly grouped.
Any ideas on the cause?