Wi-Fi networks keep dropping/turning off intermittently.

This started happening a few weeks ago. My Wi-Fi networks will intermittently just lose connection. Doesn't happen to anything directly connected to the modem via ethernet.

Sometimes they'll stay up but lose connection, while other times the network will just outright vanish for a few minutes.

My first thought was that our modem was dying.

So we upgraded, went from, I think the XB6 to the XB7, the white one.

Same exact issue. Happens with both the 2.4GHz network, and the 5GHz network. Have had Xfinity at my place for almost a decade, haven't moved anything around, no new devices, no service changes, no new neighbors that we know of, it just started happening out of nowhere.

We only have the gateway that Comcast provides, not running a third-party router, although if I can't fix this I guess I'll have to pick one up to get reliable Wi-Fi, which would be really unfortunate.

Already had a technician out, said everything is green, contacted CS multiple times, everything looks fine on their end. Like I said, the internet itself stays on and is perfectly stable. It's only the Wi-Fi acting up.