Hi I have seen this issue on a customers site before.
Do you have a gateway specified in the management interface?
If the two physical IPs of the controller and the "VIP" address are in the same VLAN then do not specify the gateway on the mgmt interface.
And also sometimes when I try to go to the management IP in a web browser, it crashes the active controller and thus cannot reach it on its own IP until a minute or so after.