Repeated brief internet outages

I’m experiencing repeated brief Internet outages/latency spikes almost daily in zip 94118. I’ve continuously logged 1-second pings to my LAN router, cable modem, Xfinity first-hop gateway (76.102.36.1), and 8.8.8.8. During the events, my router stays <1 ms and my modem stays ~1 ms, while the Xfinity gateway jumps into the hundreds/thousands of ms or times out; 8.8.8.8 shows the same pattern. My modem signal levels are currently excellent. I’d like this escalated beyond basic modem troubleshooting so someone can check CMTS/upstream history, ingress/noise, upstream SNR/MER, utilization, retransmissions/errors, and whether other modems on my node/segment show correlated impairment. If my drop checks out, please refer this to line/plant maintenance.