Quote from danielhep
Isolate the issue. If you connect a different computer through the same powerline ethernet configuration, do you experience the same problem? If you do, then the issue is the powerline ethernet adapter. Connect the computer that is having the issue directly to the router. Does the problem persist?
That is what I am doing. Ive Tested my laptop on the receiving end and I got around 5mbps. I think it was that low due to generic drivers