In the Mirroring configuration with failover and backup servers (Campus HA and DR, 2+1), ensure that you have deployed the following Omnichannel Database servers:
Omnichannel Server A as the original primary member on DC1 which is now the backup member after switchover.
Omnichannel Server B as the original standby member on DC1 if you have dual server pair setup on DC1 which is now the standalone server after switchover.
Omnichannel Server C as the original async member on DC1 which is now the primary member after switchover.