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.
You’ve been using cheap cables.
Next step up is a JCAT: https://audiobacon.net/2019/11/02/the-jcat-signature-lan-a-1000-ethernet-cable/amp/
/s if not obvious.
Someone took Monster’s “$100 gold plated HDMI” cable and one-upped it.