XB10 downstream uncorrectables keep rising after new coax; gaming stutter

We have intermittent gaming stutter across multiple devices, especially in Brawl Stars. An Xfinity XB10 gateway feeds an eero over a wired 1000 Mbps Ethernet link. Both gateway Wi-Fi and eero have been tested.

Troubleshooting completed: coax runs directly from the wall to the gateway with no visible splitter. Both connectors were tightened, then the wall-to-gateway coax cable was replaced and the gateway restarted. A temporary gateway 5 GHz Wi-Fi disable test did not establish an improvement; that radio has been restored.

DOCSIS evidence AFTER the new cable and restart: channel 24 at 999 MHz increased from 125,874 to 208,410 uncorrectable codewords in 71 seconds (gateway uptime 00:04:50 to 00:06:01), an increase of 82,536. Correctables increased from 26,570 to 44,016, and unerrored codewords from 9,138,055 to 12,276,558 over the same window. Channel power was -9.6 dBmV and SNR 38.8 dB. Other SC-QAM channels were approximately -9.3 to -9.6 dBmV with SNR 38.8–39.1 dB.

Earlier, before replacement, channel 19 at 969 MHz gained 41,830 uncorrectables in 86 seconds (227,365 to 269,195). After connector tightening, channel 18 at 963 MHz gained 44,905 in 59 seconds (107,808 to 152,713). These are within-session deltas; totals across the restart are not being compared.

Brief wireless ping tests showed latency spikes but 0% packet loss. Spikes also occurred to local gateways, so these tests do not prove wired packet loss or isolate all stutter to the cable line. Uncorrectable codewords are not a direct count of lost game packets. Nevertheless, the rapidly increasing DOCSIS errors persist after replacing the indoor cable.

Please have an official Xfinity employee help investigate RF noise/ingress, the outlet/drop and gateway, and document the measurements in a technical case. I am also engaging private live chat about this same issue; please coordinate follow-up rather than create conflicting service appointments. I can provide account details privately through the official support process.