First of all you should setup Pretty URLs in System & Settings/SEO & Statistics/URLs and Redirection
Tick the box for Remove index.php from URLs.
And set the Canonical URL as https://ahlbeck.net
see the image
Did your .htaccess file ACTUALLY get changed automatically? A lot of the time, when you click to turn on Pretty URLs, it actually tells you it couldn’t change the file and you have to do it manually. If it didn’t change your .htaccess file then concrete thinks you have so there’s a mismatch in how it creates URLs.