"Read more" button on blog post (CMS) sending visitor to "Whoops, 404..." even though blog is linked to "current blog posts"


I just used this Youtube video to create a simple columns (3 columns) blog page. Everything is fine, besides the fact that when I click on “Read more” under blog summary, the button doesn’t take the reader to the blog post but to a “Whoops, 404…” error page. I don’t know what I’m doing wrong? I have linked the “read more” button to “current blog post”.

The website is in Norwegian, so “Les mer” means “Read more” in English.

Here is the YT video.

Click here to see the issue yourself.

Thanks in advance!