Intermittent internet drops and high latency

I am experiencing persistent connectivity issues on my Xfinity Internet service that have been ongoing for several weeks. The two main symptoms are:

• Frequent packet loss and short outages multiple times per day

• Very high latency spikes, often exceeding 1000 ms

• Seen very high packet loss

I have been monitoring my connection with PingPlotter and have exported sample data for both my default gateway (192.168.1.1) and an external host (www.google.com). The graphs and exports show:

• Recurring latency spikes well over 1000 ms, sometimes several times in a single hour with no impact on local networks

• Short but frequent periods where pings time out entirely, consistent with brief outages

• The problem is visible even when testing a single wired PC directly connected to the modem/router with no other devices using bandwidth

Troubleshooting I have already done:

• Rebooted the modem/router and my PC multiple times

• Bypassed my internal network equipment and tested with a direct wired connection

• Confirmed that this occurs at various times of day, not just during peak evening hours

• Verified that the behavior is consistent across different destination hosts in PingPlotter

Impact:

• Online gaming is frequently unplayable due to sudden spikes to 1000+ ms latency and packet loss

• Remote work (VPN, RDP, Teams/Zoom) sessions are disrupted by brief outages and jitter

• General web browsing is noticeably slow or stalls when spikes occur