I was able to resolve this by using the serial console (SAC) in the Azure Portal.

1. Run cmd to open a channel and hit 'tab+esc' to switch to it

2. Log in with any account you have access to

3. cd C:\Windows\System32\Sysprep
   sysprep.exe /generalize /shutdown /oob
   

4. Wait for VM to stop, then start the VM again