Ok the preview image is 32kb and zip is 108 kb that's just one example.I tryed all that I tryed at least 10,they are all different size so I doubt it's that.
Yes, that should not be a problem at all. The only reason I asked is because I've had the same issue before and the reason for it was that the preview image was too big MB wise. In both instances, bringing the quality of the image down, which in turn brought the file size down, solved the issue.
You may need to try uploading on the older upload page, however, I don't have a link to it. Hopefully, somone will pop in that does.