It is weird. There are a couple of my articles that are PRIVATE FULL TEXT and yet it also says DOWNLOAD, and it appears that readers can download the text without asking me for permission.
Things do probably not function quite properly. But I do not know why should "private texts" be put on the network. If I have a private copy (which I do not want to be public), I do not upload it anywhere.
You as the author, while logged in, can download your own private full texts, but others cannot. To me only two of your publications (both listed as public full texts) appear available for download. The rest are not accessible.