@davemark Thinking of it a bit more, this actually looks like a security bug. Random attacker brings small device to network, starts a loop of DHCP requests from random MAC and with random UUID, watch Windows11 laptops connected to the network start stalling. I don't have the time to repro that, but it is similar to a bunch of low level attacks against OSes.
Corrected 4/21: these were UPNP notifications, not DHCP requests. No random MAC involved.