Then 0.4 or 0.5 or 0.253 or anything that isn’t the same as the router’s address or in its DHCP pool. Or shorten the LAN subnet mask on the router by one bit so the 1.x addresses are included in the subnet (though you’ll need to restart all your equipment after for that to fully take). You need to pick an address that the router recognizes as being on the LAN subnet.

Change it to 0.3.

Did something get plugged in that connected switch 1 and 2 directly, i.e. other than through the router’s switch? If you unplug one of the switches from the router does everything, including the stuff on the unplugged switch, start to work?

I have seen your symptom when switches not running STP are connected in a loop. Since ethernet loops never stop shutting everything down is the only fix.

If it has 2 interfaces, say Ethernet and WiFi, it will have two different MAC addresses, one for each. I guess they only wrote one on the box?

I see lots of T-3 timeouts and other junk in my log too, but that is DOCSIS protocol stuff that seems not to effect too much. The error counts that would be interesting would be in the “Corrected” and “Uncorrected” columns on the screen shot you posted, where all the zeros are now. They get zeroed when the modem restarts, so you need to let it run for a while to find out if there are times when the signal isn’t so nice.

200’ of wire isn’t long at 1Gbps, and wire doesn’t usually work sometimes and fail others, but WiFi does that. My money is on the link through the eero beacon as the problem.

If you rebooted the modem not long before you took that screenshot you might want to let it run a few days to see if you accumulate errors over time. Otherwise I agree that everything looks very good there, in fact I’ve never had a cable connection that nice, so don’t fiddle with anything on the coax side of the modem.

Dump the high-pass filter, that is what was blocking your upstream channels; its job is to prevent noise from customers that aren’t using the upstream. The other might be a (low-pass) MOCA filter, in which case its job is to prevent noise from customers using MOCA. If it is it won’t have an effect on your service and is probably best left in.