Yeah, You could also try running the activation troubleshooter again, but select "I changed hardware on this device recently" when it prompts you. Let me know if that works.
This happened to me. I had to use the activation troubleshooter and select the "I changed hardware on this device recently" option, even though I hadn't.
Yeah, Agreed, that command can help reset things. Also, double-check that you're signed into the Microsoft account linked to your old Windows 10 license.