I am trying to update the POS, have closed out all sessions (all POS' say "new session") but when I try to update the available product categories I receive "unable to modify this PoS Configuration because there is an open PoS session based on it."

I have re-opened, closed, and validated multiple times, shut down and rebooted both the laptop and the PoS tablet.  Is there a way to force-close the PoS in the database so that I can proceed with my updates?