Whenever I try to publish my project to Prime, I get the error: "Upload failed. The system has encountered an error. Your content X failed to upload."
I have uploaded via Publish to Devices (zip) and uploaded the zip onto Prime, and this has worked. The project looks fine on desktop, but on laptop, the formatting immediately gets messed up, which is why I am not trying to publish direct to Prime.
Too bad I have no experience with Prime. But I am puzzled by your last sentence about difference between desktop and laptop? You have created a responsive project, probably with Fluid Boxes (because that is the default workflow, for Breakpoint views you need to switch). If the 'desktop' and 'laptop' you are referring to show a different view, this is due not to their type but to a different browser resolution and/or screen setup. I wonder if you did set up the fluid boxes in a proper way, and checked this in different browser resolutions?