I don't know how this is possible, but I get
What is happening here? How is it possible? What can be done against that?
Update: HTTPS support installed, certificate made with "Let's Encrypt".
Thanks, I will soon get a certificate for the blog and that will fix it.
The blog wasn't https enabled yet, so it happened that it fell back to the next https enabled site on the same server, that's the german FAQ site.
I will update this answer then.