Page title appears randomly as "(text)" when assigning page to a parent page

I noticed that when I assign a certain page to its parent page, the page title appears as text element on the leftmost side of the page. I’ve traced the source in the developers tools/ console and it shows that the randomly appearing text of the page title is not inside any div class or div id. It just shows as “(text)” element.

I’ve been searching for so many weeks now and have no idea what I can do to solve this. I really need the pages to link to its parent so that page URLs will appear correctly.

Here’s the link to page of the test site which shows the error:
http://test.pertuatech.com/automotive/engine-oils/