Cannot change page title in WordPress scratch theme

[pthoelken]

Howdy Team. I've tried to change the page title in the normal WordPress settings and Yoast SEO settings too. Last but not least I've tried to change in header.php

<title><?php wp_title( '|', true, 'right' ); ?></title>

and in the function.php too:

function custom_title($title_parts) {
    $title_parts['title'] = "Page Title";
    return $title_parts;
}
add_filter( 'document_title_parts', 'custom_title' );

both are doesn't work. Can you help me in this section? Also as I check my Google Chrome Developer Console, he shows me no errors.

Best, Patrick.