In the Genesis themes, the featured images are automatically aligned left.
This can cause issues with text wrapping to the right if your featured image is not large enough for the space.
To resolve this issue, I recommend making sure that your images are large enough, so that the text appears below the image.
If that is not possible, then you might want to consider centering your featured images.
To do so, add this to your functions.php file:
As always, any time you make a change to your functions.php file, be ready with a fresh copy of the file, in case you need to replace it.