I uploaded a folder, but found most of the files displayed as green placemarks instead of images. These are all images that I had edited and saved as .jpg. Unedited images are displayed OK. The ones shown as green placemarks cannot be shared.
I have exactly the same problem. It took over 2 hours to upload around 280 images (3gb) and about 80 of them did not upload. They are all visible in the Cloud app but they display as a green document icon and give an error if you try to download them.
They are not particulary big and display perfectly well on my Mac.
I tried to upload one of them through the web interface and get exactly the same problem.
Cloud app is making no attempt to fix the problem, simpy says 'transfer finished'.
Very disappointed with BT Cloud. It is of no use at all if it cannot correctly upload files.