My laptop can connect to BT broadband with strong signal but doesn’t have internet connection.
Are you connecting to your own BT broadband SSID or are you trying to connect to BTWIFI?
Are you connected via WiFi or using an ethernet cable?
Are there any other devices connected to your router?
You could try right-clicking on the internet icon, bottom left and selecting "Troubleshoot" to see if anything is reported.
If you left-click on the same icon and ensure it is YOUR Hub you are connecting to. While there, ensure you're not in "Flight mode"!!!