Adding a virtual to physical HA pair for ConfigSync

Most HA configurations fail because of communication issues, typically in the misconfigured HA communication settings realm. Common causes include IP address conflicts, HA VLAN misconfiguration, mismatched software versions, and devices/systems not reachable on the network. Have you tried all the troubleshooting tips described in K13946: Troubleshooting ConfigSync and device service clustering issues? If not, I would start there. Also, there's a pretty good video on adding a new device to an existing device group on the F5 YouTube channel here: https://www.youtube.com/watch?v=Auc13Q31qUA Although this is for a Sync-Only device group, the steps are similar.