Images moved from Macbook to Dropbox folders not showing thumbnails and not opening

[FFI]

I have a dropbox family account of which I am the owner. All the images I have moved from my macbook pro to dropbox folders show the thumbnails and open on double clicking when I first add them. However, when I go back to the folders a short time later, the thumbnail image no longer shows and I have to right click to choose preview to open them (even though it is set as default to open). The images have a cloud images next to them and show zero bytes.  If I edit them from dropbox the thumbnail appears again and opens ok. It is a pain having to open every image to see what the thumbnail is and is making my workflow much longer. I have gone into 'get info' and set preview to open all files of this type but it doesnt seem to make any difference. Dropbox is still at the top of the 'ope with' list when I right click the image to open it. Help please. I am in my sixties and not particularly technology savvy although manage just fine unless its technical. 

[Hannah]

Hi there, @FFI, and thanks for reaching out to us.

If you select your images, right/control click on them and choose to make them available offline, does this issue go away?

Let me know.

[FFI]

Thank you for your response. I tried this and it will allow me to open the images now without right clicking but iy still doesn't show the thumbnail unless I click on the actual image then it shows them in the columns as an image (if that makes sense). I don't know the correct terminology for them.

[FFI]

Also, it mesas I will have to do this for thousands of images before I see what I have in the columns. 

[Hannah]

Thanks for the update, @FFI.

Would you mind sending me a screenshot of how the images appear in your Dropbox folder?

[FFI]

[Nancy]

Thanks for the screenshot, @FFI! From the screenshot, it looks like the files are still online-only and not available offline (in which case you should be seeing green checkmarks next to them). 

Can you right click on couple of files again, select the “make available offline” option and then restart your device? Do they still have the grey cloud icon after that?