How is your box connected to your router? Is it directly with Ethernet cable or Powerline Adapters?
Could you please ensure that your community profile includes your PHONE NUMBER as OCE's will need this to tie up your screen name to your account. (click on your avatar to view the information > Settings > Launch Profile Wizard,put your phone number in box, then scroll to the bottom of page and click save)
Do you have a long Ethernet cable that you can connect temporarily between the Router and the box, or move the box closer with a long HDMI lead so that you can do this?
Are all of the lights on both of them CONSTANTLY green with no Orange or Red occasional flashes on the centre one?
Is it possible for you to connect either a laptop or computer to the PLA by the box and run a speedtest from there ?
P ower L ine A dapters are notorious for occasional dropouts, which can cause your problems on these boosts, which need a continuous high speed connection. So this is just to rule these out as being the problem.