I have 4 AV2000 poweline adapters.

None are directly connected to my PC. One is plugged into the power outlet next very near the router, so plug the ethernet cable from AV2000 to a spare port in the router - Sky Q hub router.

Other power adapters are placed throughout my flat, connected to TV's ect. 

I was working fine, with all three green lights. I have the TP links diagnostic / viewer software, and could see of of my powerline adapters.  But then, suddenly, the adapter connected to my router is flashing red for power line adapter.  The flashing is not consistent.  you get steady flashing, then slower flashing, then green for 2-5 seconds - its all over the shop.

This has happened twice. I seem to get 7-10 days then get this problem agian. Last time, I switched them around, played about a bit with resetting, and eventually comes back green. But, I dont know what i did to actually achieve that. 

What is happening? I can prove it works , but why does it stop, and (hopefully) restart again?

What is plugged in on my circuit?

Next to the router based power line adapter I have a plug which goes into a 10 way multiplug, powering things like, PC monitors (x3), printer, external hard drives, ect. On the same circut, in the same room, a Denon amp and speakers. 

Can someone help me?