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.
My guess you had broken cables or defective connectors. Because even on cat5 (not cat5e) you should get much more than 7mbit, or did you have coaxial? LoL.
In my experience 90% are plugs, specially if you crimped yourself with Chinese tools