Images disappearing from region

I have a a simple region with an image and a couple of text fields. Click select or upload an image; select or upload an image (I've tried both) complete the other fields. It's a repeater so I add another. Save. All fine. Displays on web page.

Then, when I come to add or amend the region the images have gone (text is still there) and, unless I add the images again, they don't appear on the web page.

Not sure what to check.