Why Does My Ethernet Keep Disconnecting When Playing Rocket League?

I've been dealing with a faulty Ethernet cable for almost three years now. It disconnects frequently, at least every three hours, but it gets way worse when I'm playing Rocket League. For example, while listening to a song, I got disconnected twice in just a couple of minutes. This issue only happens during Rocket League sessions and not when I'm doing anything else. Does anyone have any ideas on why this is happening or how I can fix it without buying a new cable, changing the route, or switching to Wi-Fi? Thanks!