Let's take a step back are your agents able to log in to either PG? Also, how long does the failover process actually take?
It takes like 40s for the agents to be able to log in again. (buttons enabled on CTIOS). On the NRFU test i realised that active calls get dropped during this event. Another test was run on call manager subscriber: the Call manager service was restarted, and again all agents lost active calls. It seems that CCM is not failing over correctly. Phone to Phone converstations are preserved.
Your advice is appreciated.
Sounds like major issues with the voice network as the call should not drop, time to open up a TAC case you'll have to go through your gateway configs to ensure everything is setup correctly.