More Than One OG URL Specified

Hi there,

When I try to post one particular post to facebook an the header image comes up as the main image for the post, instead of the image I have set in the post and in the Open Graph Protocol plugin.
I checked using the facebook linter tool and it comes up with the message

“Object at URL ‘https://fearsomefitness.co.uk/news/christmas-offer/’ of type ‘article’ is invalid because it specifies multiple ‘og:url’ values: https://fearsomefitness.co.uk/news/christmas-offer/, https://fearsomefitness.co.uk/news/christmas-offer/.”

I have seen similar posts in the past but unfortunately the answers do not seem to work for me (or I just do not understand them)

I do not seem to have the plugins that cause these problems in other sites installed on mine and I have even uninstalled a social media plugin and tried uninstalling and installing

wordpress SEO
Open Graph Protocol
WP Facebook Open Graph Protocol

These are the only ones I could think may be doing this?

Would someone be able to look at the code https://developers.facebook.com/tools/debug/og/echo?q=http%3A%2F%2Ffearsomefitness.co.uk%2Fnews%2Fchristmas-offer and let me know what could possibly be causing this?

Thanks