When using the "Switch Group to Cloud Managed" command in Symantec Endpoint Security you see a message in the upper right hand corner stating:
Warning No devices to switch in device group "<group name>".
Symantec Endpoint Security (SES) with a Hybrid enrolled Symantec Endpoint Protection Manager (SEPM).
The sync'd group has already been migrated once before.
If a group has previously been migrated from the SEPM to SES, you may see this message. To check if the group has already been migrated: