Page title not work

Please tell me detail about that, you can send me a screenshot for further checking and let me know the position or page that you want to show. I’m still vague about your question.

To resolve this issue, you can open the header.php file in the Dashboard > Appearance > Editor then add the following code under line 14.

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

Also, you can install the Yoast SEO plugin to change/ add the sitetile and tagline: https://wordpress.org/plugins/wordpress-seo/

Hope this helps!