Intermittent Internet Outages | AI Support completely useless

Good morning, recently we received text messages about a local "urgent network performance issue" that was being "fixed". During this time our internet was out, and we received text updates. After the work was completed, we had intermittent outages and replied to the text message when it was asking if we were "still having issues" (we replied yes); it told us to just unplug the modem and router for 12 seconds, of course.

This didn't help, we gave it a day and tried, many many more times. It's been 5 days of internet outages every few minutes; my wife and I both work from home so this affects our livelihood. Throughout this time I have tried numerous times to work through the AI/Chatbot support system, only for it to regurgitate the same useless steps and refuse to let me speak with a real agent, even through chat. Same with the calls to the Xfinity support line, they just direct me back to the AI/Chatbot by sending a text link. This is extremely frustrating, time consuming, and costing me money, since my wife and I need to go elsewhere to use internet that is reliable.

I'm fully capable of troubleshooting computer issues; I'm actually a software engineer and I work primarily on firmware development; so I am open to trying anything.

Here are some details about my internet setup and issues, incase anyone actually has an idea:

Physical Routing:

[Single COAX] > [Netgear CM700 Modem] > [ASUS RT-AX58U V2 Router]

LAN Routing:

2.4GHz network, we use this for our TV, Cameras, and any guests.

5.0GHz network, we use this for phones, laptops.

We have our two primary workstations and NAS connected via cat6 cables.

The issue we are facing specifically: Intermittent (10-45m spread) outages lasting 1-5 minutes on average. Outage will drop speed from ~800mbps to under 100mbps (usually 40-60mbps), and then disconnected completely (WAN disconnect, we can still access LAN). This issue affects ALL devices, regardless of connection method (phones, laptops, TV, desktops). When not having an outage we have our normal access speed (~800-900mbps as tested with various sources (xfinity/ookla))

What I have tried:

Disconnecting everything, (starting with the COAX in from outside), ensuring all connections are clean and solid when reassembled.

Disable all VPN connections (Setup on the router using OpenVPN or WireGuard depending on connection)

Disable DNS rerouting (We typically use Cloudflare's 1.1.1.1)

Disable all wireless networks & disconnect NAS, leaving only two wired desktops (Windows and Linux)

Factory reset on Modem & Router since none of the above worked to solve the issue.

As much as I'd love to to just talk to a human on the phone who will actually listen to the problem and try to solve it for me, it seems like that is no longer possible, but I'm really not here to complain about that, I just want to get this fixed. The AI tells me I can schedule an appointment for someone to come look at this, but I'll be charged for it. Thanks in advance for anyone that decides to help.

Best,

D