Snapshot to Image to EC2 instance - How to activate Windows

Hi:

I had a snapshot of an old server. I needed to spin it back up. So I created an image from the snapshot, then created an EC2 instance from the image. Now Windows won't activate. The activation page in Windows does show the last 5-digits of Product Key 8XDDG, but says it cannot activate, providing Error code: 0xC004F074. It previously ran Windows Server 2016 Datacenter and still does, i.e. I just re-created the EC2 instance from image, I did not change Windows version.

More info. that might be helpful: I've followed the guide at https://aws.amazon.com/premiumsupport/knowledge-center/windows-activation-fails/ to activate manually. But in step 6, telnet to 169.254.169.250 fails and PowerShell command: Test-netconnection 169.254.169.250 -Port 1688 also fails. I've verified in step seven that the registry keys are correct for KeyManagementServiceName (169.254.169.250) and KeyManagementServicePort (1688). Telnet and Test-netconnection to .251 also fails. The Security Group assigned to the instance has the default Outbound rule that allows everything.

Thank you!