I bought an SBG8300 gateway a couple months ago, replacing an Xfinity rented gateway. Since then, I’ve had an issue where connecting my laptop to the wifi will cause the network to crash within about 30 seconds, sometimes faster. I have one desktop PC connected via ethernet, my phone is sometimes but not always connected and does not cause the crash, and there is a wifi printer which seems to have connection problems in general (I believe it may crash the network too, but it is hard to tell, since it disconnects at random - I believe this is an issue with the printer). My network is 400 mbps with Xfinity, and I had no issues while using their (rental) gateway.

The laptop, a Samsung Galaxy Book 4 Edge which came out very recently and is new, will cause this crash consistently. After a few minutes, the network will be back up, and from there it will usually crash at least one more time, but not always. Depending on the day, the network will either crash repeatedly, or will start working consistently after a few times. Random intermittent network crashes do occur while using the laptop, even after it has been stable for a while. This all occurs regardless of how many other devices are connected to the network.

I say “network crash” because I have confirmed that every time this happens, the entire home network goes down. The LEDs on the modem reset, as if I had just reset the router, and all devices go offline, including the desktop. Unplugging the modem, waiting 10+ seconds, and then plugging it back in does NOT improve the issue.

Please let me know what I can do to fix this issue. If you need specific diagnostic info, tell me.