I have an XB3 modem/gateway (recent vintage, replaced by Comcast after the previous one had that EOL issue) - it seems to be working ok but I noticed something curious.
When I compare the back of the modem ethernet to the results from the Admin Tool (Hardware - Lan Ethernet) the stats don't match up. When I look at the back of the modem, or run a speed test, I can tell a couple of the devices are connected at gigabit speed (solid green) on LAN ports 3 and 4. The other devices (ports 1 and 2) are connected at 100mb speed (solid amber) as they don't have gigabit ports.
But when you look at the admin tool (see attached) you get wildly different results. Is something broken with the firmware or software of my router? I feel like I've had to reboot it manually more often since getting the replacement model. Wondering if this could be symptomatic.
Similarly the "connected devices" doesn't match what's actually connected, although I figure there's some lag there.
Due to some firmware glitches with newer FW, it will be incorrect for the time being. There should be nothing to worry about. Hopefully those fixes should be coming soon. Even one of the other glitches is that the FW doesn't make XB3 reset automatically after some FW download completes. A few other glitches such as system and event logs being blank, and etc.