Intermittent speed drops for months

I've had intermittent drops for almost 3 months now. Multiple tech visits don't fix. Changed network adapter settings don't fix. New modem didn't fix. Happens on all devices Wi-Fi and ethernet. Resetting the gateway doesn't fix. Running troubleshooting on the Xfinity app doesn't alert any problem for Xfinity to actually fix. Neighbor is experiencing the same problem.

I have exhausted every internal troubleshooting step, the issue is with Comcast's network and not my internal network.