about a month ago (after six months of trouble free operation) devices in my house started dropping wifi connection to my BT Hub 6 router. This would also disable wired devices (PC, TV). The light on the router would remain blue but nothing could connect to it - wired or wifi. A hard reset would solve the problem for random amounts of time - 10 mins to half an hour before it recurred.
Once the wireless devices were disconnected all attempts to reconnect (signal still there and strong) would result in various error messages: "Password incorrect", "Authentication problem", "Cannot connect" etc.
The wireless devices are an ipad, four android phones and an android tablet, three of which can use 5GHz the rest only 2.4GHz.
Spoke to BT who said there appeared to be a fault with my Home Hub 6 and sent me a new one. The problem started again almost immediately.
Bought a Netgear D7000v2 router, set it up but the problem continued along with the router regularly freezing (unable to access via wired PC). Turning it off and on again solved the problem this time rather than hard resets. All leds remained white (good) - no faults were indicated.
I then tried a brand new TP-Link AC2800 (Archer VR2800). This router no longer freezes but all wireless devices on 2.4GHz keep dropping however 5GHz and wired devices continue to work fine. All leds remain lit - no faults indicated on the router's admin webpage either.
All the different routers firmware was updated to the latest versions - no change.
I have changed the 2.4GHz channels from "Auto" and set the channels manually, trying all of them.
I have changed the positions of the routers (although still in the same room) and all the routers have different SSIDs and passwords.
I have used a wifi analyser to look at surrounding wifi networks - none of which appear nearly as strong as ours.
The connection to the internet (VDSL) remains up at all times.
After turning off everything else in the house that uses bluetooth to no effect, my guess is (by a process of elimination) that it would seem to be interference on the 2.4GHz band but I'm not sure how to find out what that is.
This weekend I intend to ask my nearby neighbours if they are experiencing any similar issues but before I start knocking on doors any advice would be much appreciated.