Windows not showing image added to research folder in iOS

I am running scrivener for iOS 1.1.5 on iOS 11.4, and Scrivener for Windows 1.9.8 on Window 10. I am using DropBox to synchronise, with the default /apps/scrivener location.

I create a project on the iPad, selecting use drop box. I then open the research folder and import an image from the photo library. I then close the project and allow it to synchronise.

On my Windows system, I wait for DropBox synchronisation to complete, and then open the project in Windows Scrivener.
If I then look at the research folder, the image just shows as a blank card. If I look in the DropBox folder, the image is there, it’s just not shown.

I have a project ready for upload that shows this problem.