You might want to look at media converters. e.g. https://www.fs.com/products/96396.html?now_cid=1037 https://www.fs.com/products/96396.html?now_cid=1037 I use

You might want to look at media converters. e.g. https://www.fs.com/products/96396.html?now_cid=1037 https://www.fs.com/products/96396.html?now_cid=1037 I use a pair to isolate my cable-modem from the rest of my network, to the extent possible. I once lost a modem and a Unifi USG (thankfully only that) to a lightning strike. Now with the media converters, hopefully it's only a modem and a converter.