Helix not handing out IP addresses (DHCP issue)

Thanks. For some reason I never got a notification for your reply.
Turns out the issue was something else though. We had another router acting as a wired Ethernet switch for the one device we have that was still on a wired connection. That router had been misbehaving since a few days (dropping connections). So on a hunch, I unplugged it and now the DHCP problem is resolved. I suspect the misbehaving router had gone rogue and started handing out DHCP responses, or something. Our previously-wired device is now on the Helix WiFi same as our other devices, and works just fine. With the older WiFi, it did not perform well, but the Helix WiFi is clearly much stronger.