I have had this issue for a while now but paid little attention to it until the site was finished so I’m now onto bug fixing.
I cannot send a link to view the site as it is behind a secure tunnel so only a couple of IPs can access it sorry so I have added some screenshots.
On screenshot 1 you can see the featured images are not displaying just their meta.
On screenshot 2 you can see the image is in the correct box and displaying in the edit section.
Another possibly related issue (screenshot 3) is that I cannot edit or resize an image, it shows up as an error.
I have done a lot of googling and come up empty on solutions that work sorry.
Hopefully you can point me in the right direction please?