You should also link your rss feed in the meta tags of the blog page:

    <link rel="alternate" type="application/rss+xml"
    title="RSS" href="http://www.example.net/feed.rss" />

Also in the rss, this line is pointing to the wrong URL.

   <atom:link href="https://fredrikj.net/rss.xml" rel="self" type="application/rss+xml"/>