Strange Website Titles

I am getting weird website titles in Google search and I have no idea why.

Where it should just show as:

Isaan Tours | Experience the Real Thailand

I get the following:

“Isaan Tours | Experience the Real ThailandIsaan Tours …”

It appears to add the same string of words to the end of the website, page, post title. This is the same for three sites I use and the only plugin which I think could influence, across all of them, is Yoast WordPress SEO. Is there something simple I can do to correct this?

My website is here if needed:

http://isaantours.com/

Thanks all in advance.

Allan