Ok I tried to help this brother out, but getting the same issue! In the US, granted Alaska but on a 200mb/200mb fiber conection, 1 ms ping to the ISP and all that. It's definitely not my Internet or DNS or anything like that.
Basically it works fine if I select I want the image for the SP3. I click SP3, and there's a progress indicator that thinks for 2 or 3 seconds before it gives me the "download" button for the image. But if I click Surface 3, then it just gives me the download button instantly, no progress bar this time, which I'm sure is the issue. If I click the Download button, it just opens a blank page that does nothing.
Any Surface 3 users able to successfully download the recovery image? If so maybe you can help the OP out, PM him if so.