BT Smart Hub - random loss of internet

I was round at a friend's this morning sorting a few issues for her. She has BT FTTC internet. The hub is a Smart hub running firmware SG4B1000E01E (the same as mine).

Every so often, and twice in the hour or so I was there, Windows 10 reported no internet connection. The blue light on the hub stayed lit and it looked as if the laptop (Sony VAIO) was still connected to the WiFi network. Looking at the hub it was clear that the hub system uptime and network uptime were the same (to within a minute), some 17 hours from when it rebooted yesterday. So the WiFi didn't go down, the hub didn't go down.

Could it be a funny in the hub? I didn't note the IP address as had that changed I would presume the link was lost and re-established. I looked at the log and could see some SSID reconnections about the time of the loss but no obvious (to me) error situation.

Any thoughts?

Anything in the house that could be causing spikes in the electricity, or bursts of radio waves (e.g badly suppressed fridge)? Lack of DNS can also cause that error, but that shouldn't apply unless the defaults have been changed. If it's a recurrent problem it might be worth reporting it to BT.

I say the DHCP in the router just changed the IP on the PC.
I have had in the past Windows 10 say that I had no connection and at the time I was still browsing so it might be a Windows 10 issue.

I would make a not of the issued IP address given to your PC and then check after it says you have no connection.

Paul

Nothing in the house as far as I could see.

When I next visit I'll note the IP address - should have doner yesterday but too many things going on at the moment for me to think properly.