There was an issue with IP address restriction on the events server.
The events server sits behind the main EWEA server (ReverseProxy).

Adding the following lines in yellow allowed the IP addresses to be passed through.

# Deny all but allow EWEA
Order deny,allow
Deny from all
#
SetEnvIF X-Forwarded-For "mail.ewea.org" AllowIP
SetEnvIF X-Forwarded-For "home.jasonbickley.net" AllowIP
Allow from env=AllowIP
# Allow EWEA
Allow from mail.ewea.org
# Allow Jason
Allow from home.jasonbickley.net

Original reference article here