Thanks for your support.
– Are you using a valid SSL certificate?
The location where Piwik is running yes, the blog, no. The blog is non-ssl.
– Is the used URL the correct URL configured as Trusted Domain in Piwik?
Yes
– Are the no redirects which can fail?
As far as I can see no. Could you name an example?
– Is cURL enabled AND allowed?
cURL is available.
allow_url_fopen is enabled.
Does this answer it? I’m not sure how to check both of them.
– Can you have a look at your server log files? If not, please ask your host.
Yes, I can. What do you need me to look for?