My understanding is that “Modem Mode” on the Virgin Media SuperHub is is also referred to as “Bridge Mode”, so the router function is disabled. In this case, the IP address beginning with 86.16… is a Public IP address that is directly on the Internet and you should not need to set up port forwarding.
The Brume 2 should be in router mode to run WireGuard and AdGuardHome. The Eero can be in Bridge Mode (Brume 2 will be your main router), or it can be Router Mode (you will have double-NAT).
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