Why does my DL Mbps throttle down to tiny speeds with AT&T using Nord VPN?

I can connect wireless via neighbors Cox account and attain higher VPN speeds through my Nord VPN connection than I can wired via my AT&T connection. This is absurd. I am only capable of getting 50Mbps right now from AT&T. With VPN turned off, I get close to 50. Typically averaging between 42-51Mbps. However, when I turn on the VPN it drops significantly lower, averaging between 1.48-7Mbps. This is nuts. My upload returns higher on VPN than download. I have spoken with Nord several times only to find that they cannot tell me the issue when connected to AT&T. I have even used their direct servers.Is this AT&T peeping, throttling, or some other form of crap service they think is "best"? It is becoming frustrating to say the least. I can't seem to get an answer from the AT&T support besides: "Well it sounds like we need to send a tech out to fix your internal lines.". Ummm no. That doesn't seem to be the issue at all. Stop reading answers from a "choose your own adventure" book and do some actual support please.