Unable to install LED Bulb (Color)

Hi, I am trying to install a new LED bulb and followed the online instructions. I always just get to the 25% complete (on my iPhone 8), and then server error message.

I have tried to trouble shoot this using the forum and have tried the following:

  1. Resetting the bulb (on and off 5 times) and repeating the process
  2. Changing my wifi connection from 5GHz to 2GHz
  3. I have logged onto my router and tried to see if the bulb is visible on the DHCP list, and have also tried changing the DNS to 8.8.8.8 as per a previous forum
  4. I can see the bulb on the wireless network, so there is no issue with the wifi connection
  5. I have also tried on a different device (iPhone 7)

Please can you advise what else I can try?