Uppercase is different from lowercase and wordpress can’t match url

So solution is very simply

This fragment need to be pasted in functions.php

function unFocus_insensitivity() {
    if (preg_match('/[A-ZА-Я]/', $_SERVER['REQUEST_URI'])) {
        $_SERVER['REQUEST_URI'] = strtolower($_SERVER['REQUEST_URI']);
        $_SERVER['PATH_INFO']   = strtolower($_SERVER['PATH_INFO']);
    }
}
add_action('init', 'unFocus_insensitivity');

Code is working for Latin and Cyrillic letters

Материалът wordpress strange redirect е публикуван за пръв път на rosen4o.net.