Hi I've had a 3 unit Deco P9 system from February this year. The Deco is in router mode.All units are connected directly to mains, no extension cords are used. Main unit and one of the satellites are

I was suffering high packet loss on the last official firmware, and checking through the forums I came across this https://community.tp-link.com/en/home/forum/topic/225268?replyId=552006 which has a b