Packet captures show packets are consumed when attempting to ping or manage the stand-by HA monitoring IP. There is no access to management and no ping response.
You may have experienced an issue when HA is configured and you are not able to access WAN monitoring IP of the standby unit. Be sure to check the configuration in WAN Failover and LB. If the ratio method of load balancing is enabled there may be an issue with interface priority causing the packets to be consumed and not forwarded.
We can see here in Failover & LB type, ratio is enabled, we need to move the X1 to the top of the interface distribution list. Here we can see it is listed below X6 and X7 interface. Our monitoring IP address is located on the X1 so we need to set it to top priority.
3. Select Basic Failover from the drop down to adjust the interface ordering. Highlight the desired WAN interface(X1 in this example) press the up arrow to move the interface the monitoring IP belongs to up the interface ordering list.
4. Ratio can now be re-enabled by selecting ratio from the drop down and pressing OK.
5. Verify access to secondary WAN monitoring IP is now available.