I Have the same issue on a iPad Pro 12 Gen 3
I did upgrade a Gen 2 12 Pro and an Air
Same issue here as well. Cannot do OTA, and the restore images give AccessDenied. My Macs updated just fine.
For me its the same issue for Iphone X
I'm unable to download any restore image for ios or ipados.
All of them give me "Acces Denied" as descriped by the thread starter.
Did anyone succesfully download an image? Maybe through another acount or something. That would limit the problem to be an account spezific problem.
Well it's working this morning. No doubt because of this post and my feedback.
It is working foe me now. I'm not sure if the problem was fixed at Apple's end or a reboot of my wifi router fixed it.