Not always so. MAC randomisation, sometimes called private addressing, was introduced by Apple some years ago, and then adopted by Android and Windows.
Its supposed to prevent a device from being tracked from one wireless network to another. It doe that by assigning a random MAC address to the connection, instead of the real device MAC.
This causes all sorts of issues, especially on the home hub, as it creates lots of "unknown device" entries, and eventually uses up all of the internal routes, preventing new connections. It alse upsets any access controls.
With third party routers, these "stale" entries are removed by a soft reset or power reset, but not on the BT Home Hubs, owing to a very old bug in the software.
The only way to remove these entries, is with a factory reset.
Unless yo disable MAC randomisation on any connected devices, the problem will eventually re-occur.
