[SOLVED] 2 WAN interfaces, one shows up in Services -> DHCPv4

[OmnomBánhmì]

I have a 3-port box with OPNsense on - a new setup. Box connects to a VDSL line on WAN1, which it does, and a fibre connection von WAN2, which it does. This one is set to a static IPv4 address and works as intended. I have both WAN show up under Interfaces -> WAN, which is fine.

But surprisingly the WAN2 shows up  an an interface I can enable DHCP on Services -> DHCPv4. Certainly it is not meant be this way. Why does it show there, and what did I do wrong to put it there? Most importantly, how do I fix it?

[OmnomBánhmì]

So I've checked on other machines - than WAN connections always do show up in Services -> DHCPv4, that is except if they are PPPoE links.

While that still seems odd (why show WAN connections here at all), I'll decide to not care much.
Thank you for listening.