I am not sure what your exact issue is, but I had an issue, which actually dates back to Mavericks....
It would ask me to confirm with my IOS device, however my IOS device would never get the request.
It turned out, that in the settings box that showed my area code it had a blank box, and in the phone number box, it had my entire phone number. As soon as I corrected that, all of my iCloud keychains started to work.