The desktop did come in low so test that location but with the laptop. If still low my thought is that it's on the wrong side of the mains. An electrician can move that over to the same side as the router.
I bought 3 powerline adapters with passthrough. One I connected to my router and the other to my desktop computer and another to my laptop. On my laptop I get 25 Mbps and on my desktop I get 6 Mbps. Via wifi I get 33 Mbps on both and my total internet speed from ISP is 50 Mbps. On my desktop into the plug that I have my powerline adapter connected I have my phone, my tv and my desktop computer attached via an extension cord. Is this reducing my bandwidth at my desktop. Anything else I can do to improve my bandwidth on powerline adapters. I was expecting to get more than wifi speed via powerline adapters so that my steam link doesn't lag.