I have the multi kit with a base module sited next to the HH5. I then have two extender modules placed in parts of the house which can only receive a weak Hub signal. Both have worked without issue for more than a year.
Recently one of the units, whilst showing a full signal on my phone or tablet, will refuse to connect to the internet for anything between 5 minutes or an hour. The other unit works fine during this period, as does the signal from the Hub.
I have done a factory reset and recloned. I've 'forgotten' the signal and reconnected. I have rebooted the Hub. BT customer service thought the problem might be incompatibility of the Hub and the extender signals and twiddled with the signal frequency of the Hub. All to no avail and very frustrating.
Any options left before I chuck the **bleep** things in the bin and buy new ones?
Fingers crossed but I think that I've fixed it. I've moved a nearby plug-in door bell....the sort which sends a signal from the press switch to the plug-in bell unit. I think that the unit was interfering with the hotspot. So far so good!