If you get this error when you configure the HomeKit accessory, please do as follows:

a. Connect your iPhone or iPad to 2.4GHz Wi-Fi network to add the accessory. If the Home app keeps failing, you can turn off the 5GHz Wi-Fi of your router temporarily until the accessory is successfully added. 
  
b. Make sure Local Network, Location Services, Precise Location and Home Data have to remain on in Settings -> Meross.

c. Make sure VPN / DSN services are disabled on your phone before adding any accessories.