When accessing http://domain.prod.acquia-sites.com, you get redirected to https://www.domain.prod.acquia-sites.com and you obtain an error message
This redirection from bare http to non-bare https domain comes might come from some code in your .htaccess file
# ensure www.
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*)$ https://www.%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
# ensure https
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]As explained in the documentation Excluding Acquia domains and non-production environments, you can exclude Acquia domains from this redirection, adding the following line to the rule in your .htaccess file
# exclude Acquia domains
RewriteCond %{HTTP_HOST} !\.acquia-sites\.com [NC]