Page Title Bug (WP blog post)

Hi,
Page title of Blog main page is added at the end of blog post page title! I need to remove page title of main blog page of each blog post(, since it's duplicate content + creates a very long page title).
For better understanding:
– See also attached screenshot with explanation!
– URL: https://www.lottosend.com/blog/
– Current plug-in for meta tags: "Add Meta Tags" / George Notaris.
Thanks!
Mike
Page Title Bug (WP blog post)

See original post by Michel Z.