Hi,
Did you get insider activation key when you register it?
If yes, we could try the following general insider activation key to activate your system.
Windows 10 Home: TX9XD-98N7V-6WMQ6-BX7FG-H8Q99
Windows 10 Pro: VK7JG-NPHTM-C97JM-9MPGT-3V66T
Windows 10 Enterprise: NPPR9-FWDCX-D2C8J-H872K-2YT43
Here is resource link for more information: Windows 10 Preview Product Key
As your issue is more related with insider system version, I would recommend to contact with that specific forum for insider system: Windows Insider Program
Please note: Information posted in the given link is hosted by a third party. Microsoft does not guarantee the accuracy and effectiveness of information.
If my information or redirection is useful for you, please accept it as answer. It will help other customers find useful result more quickly.
Bests,
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