If the issue is a network WAN outage, it is most likely that the initially active sequencer is still active and the work in the primary data center was not interrupted. In this situation, the work in the second data center with the standby sequencer is halted because it cannot connect to the active sequencer. However, any applications connecting to the active sequencer are still online. For this reason, there is no automatic failover to the standby sequencer.
If the issue is a WAN outage, do not fail over to the standby sequencer. Doing so is unnecessary and can result in a split-brain failure leading to irresolvable data inconsistencies. The correct course of action is to work on resolving the network outage.