I have FTTP as you know I was using my netgear but I noticed a slow down in speed to around 300 odd on the ethernet cable I use a netgear nighthawk but its been hovering around 300 mb
During the testing with bt they asked me to place the router back in theirs and low and behold the speed was fine. getting my full speed according to fast.com
I am wondering has bt started to limit the username and passwords of the bt login we all use to 300 mb
it's unlikely BT would throttle a 3rd party router, it's more likely the router itself.
does it have the most recent firmware?
I have the same issue with the nighthawk x6 r8000. Setting the speed manually and then disable qos worked to begin with but issue has returned. You found a solution yet?