I've tried using Chrome, Edge, and Tor the first two with and without add blockers and have had no success.
I also tried a VPN to appear to be in a few different countries..
What's strange, is that most of these books have a non zero value for the # of times they've been downloaded, assuming that is an accurate count.
I've also tried to read on line and that stated there was an error.
As I said previously, the problem went away so hopefully they'll fix it again.