Menu item for a single page doesn't work

Hi,
I have followed the instructions on link demo.hotjoomlatemplates.com/one_page/ section "VI. Template Features" in order to add a new menu item that would point to a single article.
"You need to make an article page and to create a menu item (type: single article) that's assigned to the article"
Although the link field on the menu item page is showing 'index.php?option=com_content&view=article&id=113', which is the correct link for the single page, when I browse the site the menu item just links to each alias (/fagaki2) and does not load the page

site url
fagaki.demos.my-portal.gr/demo4/
menu item link
fagaki.demos.my-portal.gr/demo4/index.php/fagaki2
single page link (correct link)
fagaki.demos.my-portal.gr/demo4/index.ph...t&view=article&id=89

Can you help? Thanks in advance

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