Secure Connection Failed An error occurred during a connection to katescastle.com.au. PR_CONNECT_R

How do I resolve this?

• The web site is self hosted of a windows 10 desktop via ISS
• It is https with certificates created with 'Certify the Web'
• The web site was running just fine.
• The NBN (national broadband network - optical) went down for a day.
• It has come back online and my WAN address changed.
• I have updated the WAN address for the domain at 'web central'
  

   

• However the web site will no longer load.