Naja, irgendwas muss anders sein. In meinem jugendlichen Leichtsinn würde ich behaupten, das du eine oder mehrere Weiterleitung (vermutlich Default Einstellungen, so wie mein Vorredner das schon vermutet) übersiehst. Guck doch nochmal nach 
Hast du den Artikel des Supports gelesen? Ich denke das löst dein Problem :
If you use Cloudflare's Flexible SSL service and see mixed content issues or redirect loop errors, first ensure that there is no SSL certificate installed at your origin. If there is, then you shouldn't be using Flexible SSL and should instead set it to Full or Full(Strict).
Additionally, please ensure that there is no redirect set up at your origin from http to https, as this specifically would cause the redirect loop.
If none of the above applies, consider the following:
- If you are on an Apache web server, ensure that you have Mod_Cloudflare installed.
- If you're on Nginx, or Mod_Cloudflare does not automatically resolve the issue, ensure you have our official WordPress plugin installed.
- Should you continue to find issues, you may have URLs incorrectly formatted in your HTML or database, in order to resolve this please install a Mixed-Content Fixer plugin. We have had success with SSL Insecure Content Fixer.
Other Users
If you are using Cloudflare's SSL in Full or Full (Strict) mode and you find you have mixed-content issues, it is likely the case that you have absolute URLs hard coded into either your HTML or in your database. Please install a Mixed-Content Fixer plugin which should automatically replace the http with https in these sections. We have had success with the SSL Insecure Content Fixer plugin.
Beste Grüße
