Media doesn't load in Adobe Express

I've just starting using Adobe Express and none of the media (video, images etc) load in thumbnail view. When I try and add one of the Adobe Stock images, I get the message that thje "File is not compatible".

I can upload my own images but these also do not display as thumbnails, although they are visible when I add them to the canvas.

I have an Adobe Express Premium subscription and am working on a Windows laptop. I've tried Chrome and Edge as well as using Incognito mode but no luck.

Can some help?