If you receive the error, “Something went wrong during setup,” the product may be having difficulty joining the Wi-Fi network or there may be an issue with the Apple HomeKit platform.
Please try power cycling the product by unplugging it and plugging it back in or pressing the reboot button for in-wall products. Then, try to complete the setup again.
If power cycling the product does not resolve the issue, open the Apple Home app. The Home app may prompt you to enable certain settings to allow the setup to complete. If the Home app shows "Loading Accessories and Scenes" it will prompt to reset the home configuration if there is an issue completing the sync.
For troubleshooting steps specific to your product, click on the link below: