blog is only showing one post

I have implemented the highend theme on this site:

http://savethedateevent.co.uk

The theme is perfect and I have done a moderate amount of modifications to the child theme.

I have an issue with the blog page:

http://savethedateevent.co.uk/blog/

It is only showing one post – I have tried all the blog layout options with no joy, the footer widget however is recognising more than 1 post. I have the front page set as a static page and I have tried setting the posts page to the blog page and also tried leaving this option blank. Both options still only show one post.

Any advice or help would be much appreciated.