After seeing that my wireless speeds were much faster than the speeds I was getting over Ethernet, I decided to invest in some new cables. I didn’t know it before, but I saw while I was changing them out that my current cables were Cat 5e. While putting my network together, I had just been grabbing whatever cables I could find in my scrap drawers. Now I have Cat 8 cables and my speeds jumped from 7MB/s to an average of over 40MB/s. It’s a much bigger improvement than I expected, especially for such a small investment.
Cat5e will also do gigabit, so yeah it wasn’t a cable spec issue. Bad cables is likely dead on.
5e will give you issues with good cable if it’s a long run as well, but by long run I mean 300ft.
100m is the spec max. More than that, you need a powered repeater (i.e. baby switch). And you won’t get 100m if you have bad cables.
I once saw a run in a cruise terminal, out of the cruise ship, down the gangway, along the terminal hallway, and through two more little switches just sitting on the floor next to an outlet. Not sure why they needed that run, but that’s what they did and it worked.