I fixed it. for anyone who had the same problem, I found it in content-single.php, the relevant line of code below, $thumbnail = ‘medium’; and changing it to full instead.
<figure class=”single-thumb single-thumb-full”>
<?php
$sidebar_layout = acmeblog_sidebar_selection();
if( $sidebar_layout == “no-sidebar”){
$thumbnail = ‘large’;
$no_image = get_template_directory_uri().’/assets/img/no-image-840-480.jpg’;
}
else{
$thumbnail = ‘medium’;
$no_image = get_template_directory_uri().’/assets/img/no-image-690-400.jpg’;
}
if( has_post_thumbnail() ):
the_post_thumbnail( $thumbnail );
else:
$img_url[0] = $no_image;
?>
<img src=”<?php echo esc_url( $img_url[0] ); ?>” alt=”<?php the_title_attribute(); ?>” title=”<?php the_title_attribute(); ?>” />
<?php
apologies if anyone worked on this.
cheers