my site show this symbol (::) between site title and tagline

Question

i have a web site with a problem in a tag "<title>" , i see between site title and tagline this character (::) in home page and only one (:) in other page, in my header.php theme i have this :

 <title><?php wp_title(); ?></title> 

i tried also :

 <title><?php wp_title(''); ?></title>

but i see same character:

after this i tried :

<?php $symbolo="|"; ?>
 <title><?php wp_title($symbolo); ?></title>

and show this in frontend-sourcecode title:

this is a title :| this is a tagline

in normal circonstances <title><?php wp_title(); ?></title> with this i see for homepage this:

this is a title :: this is a tagline

and for other page , i see this:

this is a title : this is a tagline

now i want use a symbol (|) instead (:) like this:

this is a title | this is a tagline

how solve this ?

Answer 1

Do you install any SEO plugin? Yoast SEO maybe. Or plugin that related to SEO. It usually overwrite the title setting. Check your plugin first please.