Hello! Let me know if this information would suffice- it sounds like you want to change the management interface to a data interface (WAN): https://www.cisco.com/c/en/us/td/docs/security/firepower/670/configuration/guide/fpmc-config-guide-v67/device_...
Sorry for the delay in getting back to you. It has been a bit busy on my end as we wrap up April!
I've been taking a look at similar issues encountered by other customers. It might be fruitful to generate a DART and send it to me through a private me...
