Agree - I have a fiber setup so my "modem" is just the ONT for the
fiber/RJ45. Tried plugging direct into that, but same issue even after
power-cycling that for grins and giggles.
I've got this EXACT same issue. Parents were using it for about 3
months, I brought it home and got it setup. Router & 1 node work find
(factory reset both), and one node just refuses. Followed all steps.