Theme: Twenty Fourteen – Featured Image covered by post text

I have a blog using the Twenty Fourteen theme. Every time that I post a blog post, the bottom of the featured image that I make on Canva is covered by the top of the block of text of the post. I usually use the ‘blog title’ option on Canva when I produce the image, but I recently tried to use the ‘Facebook cover’ option, and also tried making it a custom size to see if I could avoid the problem, but none of them work and it seems that the text just moves up to block the same amount of the image as it did originally.

You can have a look at my blog at http://jessicawithjetlag.com and see what I mean, it’s happened with the only two that I have made, and is happening on one I am about to publish. Please help – I am a newbie!