I've a newly installed pfSense box with several VLAN interfaces (I do not use the LAN one).
I also use dedicated DNS servers in my setup (BIND), and pfSense is taking care of all the DHCP services.

For one (only one) of the VLAN interface, I configured the pfSense DHCP server to send Dynamic DNS updates to my DNS servers (configured key, etc.), and everything works great.

However, looking at what my DNS server receives, I actually noticed that it is also receiving DDNS updates from pfSense for another VLAN interface, for which I never configured anything (I don't want DDNS updates for that other VLAN).
Is this the expected behavior?
It was my understanding that the DHCP configurations from all interfaces are independent and would not impact one another.

To go deeper in my investigation, are there some configuration files I can check from the CLI?

Thank you for your help.