You should configure the BlogPost widget to point to a new page that holds the BlogPost itself (details). You can do this by editing the widget properties. (Widget Properties -> Single Item Settings)
Sorry didn't explain this very well, the problem was having two widgets doing the same thing on the page and they were following each other.
The solution is to change the urlprefix as described in this post I found googling around:
I see. Yes, that would be the appropriate solution. Glad you have worked it out.