Pagelink is not getting converted

Your software
My Mautic version is: 4.4.5
My PHP version is: PHP Version 7.4.3-4ubuntu2.17
My Database type and version is: 10.3.37-MariaDB-0ubuntu0.20.04.1

Your problem
I have setup a campaign that is used for double opt-in.
I added a pagelink to a button element. This pagelink is not getting converted to a real link in the email client.

It works when I look at the preview, but it does not work for real mails send to clients.