Welcome to this user forum.
If its a home hub 6, then its probaby broken. Ask BT for a replacement.
Once the hub is connected and light blue then there is no flashing lights whether wireless or wired
try factory reset by pressing the recessed button on the back and holding until lights flash. If that does not fix it then try and get a replacement
How do I know if it is a hub6
It will say on the home hub, its often called the smart hub.
If it's a hh6 then there is no flashing lights on the Ethernet ports on the back when in use
Try the factory reset
have you tried connecting to hub with ethernet and then to pc/laptop missing out the switch