Hey @gbassoc, having this issue also, I temporarily fixed it by updating the widget.php file, removing the content filtering (which adds paragraph tags and so forth)
Original:
echo apply_filters('the_content', get_post_field( 'post_content', $instance['block'] ) );
Edited:
echo get_post_field( 'post_content', $instance['block'] );
This is an imperfect solution, there should be a way of applying the filters without the extra content, will follow up if there’s a better way.