404 not redirecting

Hi there!

Your plugin was working just fine for almost a year, thanks for that!

But now it seems to be off. I’ve set the following URL as 404 (as it was before): https://meetsomnox.com/dreamland

But now it sends people to some kind of summary of my blog posts. Really weird: https://meetsomnox.com/test404

Do you know what might be the problem? Thank you in advance.

The page I need help with: [log in to see the link]