Found then answer
We found that the .htaccess file in
wp-content/uploads/ was preventing you from loading the images:
<Files *.php>
deny from all
</Files><Files *.css.php>
allow from all
</Files>
The file has been renamed from .htaccess to .htaccess.bak to prevent the above file access rules from coming into effect and images are now being displayed correctly in the Media Library.
Whoop