Double Images in Posts

Hi

I am using User Submitted Posts plugin with OceanWP theme and to my dismay find that when I post using a ‘Submit Post’ page that I have made (using this plugin), the image that I use in the post (that I mean to be a featured image) appears twice – one as a big feature image (which is how it should be) and another as a tiny version at the top of the article (inside the article though) so I get two images one the bigger featured one and another the tiny one.
Can anyone let me know how to remove the smaller image?

Thanks