The other day I was working on one of my projects and I encountered an unexpected behavior: if you write the URL of a page in a WordPress site incorrectly, WordPress will try to guess what page you were trying to access and “fix” your request so that you get the proper page and not a 404 error.

WordPress tries to guess the URL if you typed it in wrong.

Is it good or bad that WordPress tries to fix a URL that does not exist instead of returning a 404? According to bug #16557 reported 9 years ago, there should be a filter to deactivate this behavior if the user wishes so. But although we have a patch for it, for some reason it never made it into core so… what if you wanted to deactivate this behavior?

To solve it - follow the link:
https://neliosoftware.com/blog/devtips-how-to-stop-wordpress-from-guessing-urls/