The following list describes known issues in the VM-Series
On Azure, Active/Passive HA configurations
that use a floating IP address sometimes experience loss of traffic
Upon failover, Azure starts moving the floating
IP address from the primary to the secondary. If the HA pair is
restored and control returns to the primary before the IP address
moves to the secondary, traffic is lost.
To restore traffic, you must temporarily suspend
the primary so that the secondary (which has the floating IP address)
This issue is fixed in VM-Series plugin version 1.0.12.