Same here. Yeah, that's solid advice. One extra thing—sometimes just leaving it connected to the internet for a day or two lets it sort itself out automatically.
Can confirm. You could also try running the Activation troubleshooter again, but this time choose the "I changed hardware on this device recently" option. Let me know if that works.
You could also try the slmgr /rearm command in an admin Command Prompt, then reboot. Another option is to contact support directly through the activation troubleshooter—they can sometimes push a fix from their end.
Agreed. Yeah, that's a good first step. Also, try running the Activation troubleshooter again after a full restart—sometimes it just needs a second pass. Good luck!