FDM HA Switch : Peer fails to get into Active state

[madasamy461993]

The Active unit may occasionally switch to Failed state and then Standby Ready state due to an Interface check error during a deploy to an FDM-managed HA pair.

[MHM Cisco World]

https://www.cisco.com/c/en/us/support/docs/security/secure-firewall-threat-defense/221012-configure-ftd-high-availability-using-fd.html

Check this guide if not help you let me know 

MHM