You will need to reset the Wi-Fi configuration while connected to the new network using an Ethernet cable.
Follow the step-by-step guide below:
This will show the Hub Detail page, which contains the Wi-Fi network.
The Hub will restart and can now be reconfigured to a new Wi-Fi network.
The Hub LED will flash aqua before turning a solid magenta.
Select Configure, and follow the prompts to join the Hub to the new Wi-fi network.
The name previously assigned to it, all previous shades, rooms, scenes, and schedules will be intact.