Hello, I’ve purchased Cubase Artist - Upgrade From Cubase AI with USB dongle. Now I registered Cubase AI 10 and purchased seperently Cubase Elements 10 (updated to 10.5) but when I trying register new key I got an error “Currently, there is no license available which can be upgraded by your upgrade license. Please connect an USB e-License, which holds an appropriate upgradeable license, to your computer”. New Cubase is called as “Cubase Artist 9 UG AI (DAC)” but in left corner of box is only information about “*requires Cubase AI version 6 or higher”. Now I am powerless without any solution or method to solve this issue. 
You will need to move your AI license to the USB dongle before upgrading.
I’ve tried this but without any result.
Can you post a screenshot of the eLCC window (Make sure to edit out any serial numbers)
Also try to run maintenance in the eLCC.
Also tried, still no result.
Screenshots here. From first step to last stage of registration.
Also Cubase box here (captured by myself): https://i.imgur.com/1JYGV5l.jpg
Well, I’m out of clue about this. Cannot see anything wrong about your steps.