Gaming Lag and Packet Loss Issues

Hello, I am having significant packet loss and network interruption issues when gaming on a PS5 with wired (Ethernet) connection. I have tried all of the basic, recommended fixes (restart modem, check wires, replace Ethernet) and nothing seems to work. I am realizing the more I look into it, packet loss can be caused by congestion/signaling issues. I went to my local xfinity store and none of the employees were helpful regarding the problem. How can I resolve this issue?