This is more an observation, although I would be interested if anyone can provide additional insight, and the experience may be of use to anyone with similar symptoms.
I have used a HH5 for years with no problems and my old devices were only capable of using the 2.4GHz wi-fi, which was fine. I recently had to upgrade my iPhone and iPad due to apps no longer working, and I found I was getting continual disconnections from wi-fi on the new devices. Initially I thought it must be an Apple problem, but then I found that my new Dell desktop exhibited the same symptoms when I tried wi-fi. I had never paid much attention to the wi-fi setup and have limited knowledge in that area, but after much googling and trial/error I eventually found that the problem appeared to be with the 5GHz network.
I tried separating the networks with a different SSID for 5GHz. The Dell managed to connect to 5GHz once although it said there was no internet access. Subsequently it just said it couldn't connect. Both the iPad and iPhone repeatedly said that the password was incorrect for 5GHz.
I switched off the 5GHz and everything connected ok to 2.4GHz. The disconnections I had previously experienced with the new iPad and iPhone no longer occurred. So I concluded that the HH 5GHz wi-fi was faulty. I contacted BT, who agreed and sent me a new HH5. Unfortunately the new HH behaved exactly the same as the old one.
I contacted BT again and was told that there's a problem with my line which is stopping the 5GHz from working. The previous person had told me my line was fine, and the upload/download speeds were within spec.
I couldn't understand why the external connection would impact the wi-fi signal between the HH and the clients. I tested this by removing the external connection from the BT master socket to the HH, and sure enough I was able to connect the new devices to 5GHz with no problems, albeit with no internet access.
An engineer is due in a week or so, but I thought I would share the experience and ask if anyone can enlighten me on the connection between the external line and the internal wi-fi.
Solved! Go to Solution.
The engineer determined there was nothing wrong with the BT line and couldn't understand why the previous person had reported a fault. After trying a few things he eventually fixed the 5Ghz wi-fi channel to channel 48, which is something I hadn't thought of trying (although I could have if the support folk had suggested it). The 5Ghz band has its own SSID.
Having fixed the 5Ghz channel I was able to connect iPad, iPhone etc with no problem.
That was over two weeks ago and it had been working ok since then. Today I had the same problem with my iPad/iPhone. Neither would connect to 5Ghz. Each time I tried it said the password was incorrect although it wouldn't then accept the correct password.
I logged onto the Home hub and the 5Ghz "Current channel" was still set at 48, although I noticed that the "Channel selection" dropdown said "Automatic (Smart Wireless)". I changed that to channel 48 as well and everything was then fine.
At least I now know how to fix it although I don't understand why the channel selection option would have suddenly changed.