Slow speeds to the Gateway

While running a speed test with the Xfinity App, I am getting very slow speeds (around 1100Mbps) even though I was upgraded to 2G.  I am really tired of contacting cust service and they just asked me to restart the modem with no resolution.  I am not talking about a speed test to my laptop or computer: I am talking about the speed to the gateway (To my home).  I am not having a steady signal, because I see the fluctuations while running the test with the Xfinity App.  Can a Supervisor from the Hartford County in Connecticut check this issue?  I've been having this issue since July 23. 2024 when the speed upgrade was made.  I've never had issues before with my speed. Please help me