Images not displaying, path in is missing. Issue not found on another server

I have a problem with displaying images on the new server. On another one everything was working OK. I moved the site to names.co.uk and some of images are not displayed.

The weird thing is that it seems the problem is in the code itself. I inspected the code and the path to the image is missing:

Below the problematic image there is another which is displayed OK and the code looks like this:

What could be the reason that some images are displayed and other are not?
I thought it’s something about permissions, but I’m not sure now.

I also edited the actual page and selected the featured image – it didn’t add this image. It still displays the page like there is no featured image. Is this an issue with some sort of communication between the gallery and the page?

I set permissions of uploads server to 755 via FTP. Maybe the upload_path is incorrect? It is blank at the moment when I open options.php

Please help. Thanks