Why is my newly created organizational unit (OU) not appearing in the list of OUs for use in automatic device labelling rules?

For Nanitor to recognize the organizational unit (OU).  At least one device that has the OU needs to check in system information.  By default this happens every 6 hours. To expedite the process, go into device detail for a device that is known to be in the OU and request a recheck.  This may take up to 10 minutes but it will update the OU information, including adding any missing OUs to the system.  As long as the device belongs to the OU in question.