Intermittent packet loss

Starting around 2 months ago I have been experiencing intermittent packet loss for around 5 seconds at a time, every few hours. It's been incredibly annoying for video calls when working and when gaming*. I assume something must have changed since I've been using xfinity for almost a year and a half and have never encountered this problem previously.

I am on a wired ethernet connection. I have tried switching ethernet cables, restarting my gateway (through app and through the button at the back), and unplugging / replugging every cable. The issue persists.

*Interestingly enough when I'm gaming, the packet loss seems to be one way; my inputs do not register but I can still see updates from the server.