To explain, I get "Contact us to continue" when I press "Enroll Now". I get no change to upload any id documents or other data.

Also what is interesting, when I open iTunes - Account, and view my devices there, my device is missing. But it is visible on appleid.apple.com and of course the device list on my all my iPhones and iPad

My current device was used by my wife previously, and it is still showing in her iTunes, although her appleid.apple.com is not showing it

I had the same problem, then at some point the error message changed to "Contact us to continue". I have contacted Apple Developer support many times in the past months, and no solution. Apparently there is a bug in the system. I have reported it in the Apple Feedback app. I have been very depressed about this, because I quit my well paid job to make an app, and I can't even debug it. I don't know what to do, I have asked Apple Developer for a phone number to call, but no answer. I can only send message to them from here, and then I get an email, but I can't respond to it, or they have never responded back. I noticed that my device list is wrong on iTunes, all my recent devices are missing, including my Macbook, but correct on appleid.apple.com. It even feels that Apple don't care about me. My suspicion is that this is caused by me changing the appleid email in the past.