Office Key Replaced with a Different One

Hello.

I purchased an Office 2016 Pro Plus key and installed it normally using the setup.com link.

I checked my Microsoft account and found that the key is linked to my account, so everything seemed normal. However, when I checked the license using the DOS command, I found that the last five characters (-XXXXX) do not match my key!!! I uninstalled Office using the uninstallation tool and reinstalled it, but still got a different key. I even formatted my PC and reinstalled Office, but the result was the same.

My question is, why did I install one key, but the key displayed on the license is different?

Thank you