Customers using RTS ODIN or QSC Core devices with failover to redundant system devices are not fully supported in DDM 1,7. This is due to an issue with peer group IDs in DDM 1.7 specifically. Upgrading to 1.7 whilst these devices are using the failover feature will cause these devices to go offline.
The issue will be addressed within the next 1.8 release and the current recommendation is to continue using DDM 1.5 until then if you use these devices within DDM.