I did fond resolution:
This happened to me too. You have to make sure that your title section in the header.php file is exactly like this:
<title><?php wp_title(''); ?></title>
I made this change on the header.php file, no further issues.
A quick update: I have learned that this is being caused by the Yoast SEO plugin. This was verified by checking the code with and without the plugin activated. Now to figure out how and why it is causing that.
