I tried exactly the same steps with a local copy of the site and it works fine - the test link and also when I make everything active. The hosting company for the site that doesn’t work say there is nothing wrong at their end.
Apologies for the delay in my response. Sometimes web hosts will block requests from our CDN endpoints thinking it is automated traffic (because of the source IPs come from data centers around the world).
If your web host has sensitive thresholds or IP reputation based security rules, they will block our requests to fetch and cache elements from your site. I tried to load your website from one of our endpoints to see and indeed the request is getting blocked :
# curl -sSL -D - https://www.slpit.co.uk -o /dev/null
curl: (7) Failed connect to www.slpit.co.uk:443; Connection timed out
So you either need to get your web host to adjust these types of rules or you can email support@shift8web.com and I can provide you with a list of IPs of our endpoint servers to whitelist on your side. Note that our CDN works exactly like most other common CDNs so this would be a problem that is not limited specifically to our CDN. IF other CDNs work it might be because they are more popular or common and therefore pre-whitelisted perhaps.
I hope this helps and will wait for you to follow up.
