is it configsync address or network failover address?
if configsync, i do not think it is allowed to use management ip.
Defining the ConfigSync addresses for a high availability pair is an optional configuration element. If you have configured network mirroring addresses, the BIG-IP system performs ConfigSync operations using the mirroring addresses. In BIG-IP versions 9.4.2 through 10.x, you can define explicit IP addresses for ConfigSync traffic. This step provides the advantage of separating mirroring traffic from ConfigSync traffic.
In most versions of the BIG-IP system, you must configure the mirroring IP address using a non-floating self IP address, as opposed to the management IP address. In BIG-IP 9.1.2, 9.2.x, 9.4.x, and 10.x, the BIG-IP system prohibits you from configuring the management IP address as the mirroring address.
sol11736: Defining network resources for BIG-IP high availability features (9.x - 10.x)
https://support.f5.com/kb/en-us/solutions/public/11000/700/sol11736.html