For anyone still struggling with this, I found a solution that worked for me.
My situation was slightly different. I set up Windows 11 ARM on my work Mac and wanted to activate it with a Volume License Windows 11 Pro key from my workplace. Activation failed and the error returned was 0xC004F213. The natural conclusion was to try the troubleshooter. Troubleshooter said either contact support or buy a new license. I chose to contact support, but because my Microsoft account is a business account, the Get Help login screen wouldn't even recognize my account.
Googling the error code, I found
this guide to resolve the same error code, but in Windows 10. The section that finally resolved the issue for me was "Use a Generic Key". Basically, you disconnect from the internet, input the generic key which will upgrade your "Home" installation to Pro, then restart the computer. After you restart, connect to the internet again then change the license key to your valid key. Voila, Windows 11 Pro for ARM activated on my M1.
I suspect the fact that my key is a volume license key was not relevant, and that it simply would not activate on a "Home" installation. Using the generic key to update to Pro seems like the real fix.
It may also be worth noting that I'm on the Insider Beta channel, though I suspect that makes no difference.