Inconsistent powerline connection

[N0seBone]

Around 6 months ago, I purchased a Powerline AV500 kit because I couldnt stand my slow, inconsistent wireless. When I first got them, my connection to the router was great. I got my full internet connection, 15 down and 5 up, but a couple weeks ago I started failing me by dropping to 5 down and 5 up or lower and sometimes it lost connection. When it loses connection, all i have to do is unplug and plug in and it will start working again. However, that doesnt help my connection when it is lower then usual. Does anyone have any idea how to fix this or think they know what causes it? 

[RedPanda]

I used to have this problem with powerline. My solution was running a hardwired cable. Temporary solutions included resetting the router and re-syncing the adapters on a power strip together. Interference from electronic devices was the cause for my problems, like if the washing machine was on.