Over the past 7 months or so I have been having wifi issues now and again and altough the BT wifi help has fixed the issue every once in a while the problem seems to come back and when I phoned BT wifi help a few weeks ago I found them to be less than helpful.
I have been using the Home Hub 3 since 2011 and still use the old white Openrech modem.
All lights on the Home Hub 3 show blue but once in a while the wifi is slow on my IPhone/IPad Mini or it just buffs. My sister has also once in a while notice slow wifi on her IPhone whens shes poped round to the house for a hour or two.
I have 3 times now changed the wireless channel on the Home Hub 3 and reset the hub twice I was told over the phone.
They even tested the landline twice. All works fine via ethernet.
I also have the Amazon Echo conected via wifi and every 4 or 5 weeks it loses the wifi conection for a few seconds. I also use two TP-Link wifi smart plugs.
I got a small felling that though time I may need a new routre.