When looking at the Keys after your MAS is done and reboot...

[MK202407]

First a nice job, everything work fine and OS changed from 11 Home to 11 Pro.
Used a tool to look up the new key in 11 Pro. Original OEM 11 Home key also shoved up but know that it is hard to get rid of it.
When looking at the new 11 Pro key...
Is it not the Key we used before for 10 Pro before activation?
That ends with -9MPGT-3V66T?

[thecatontheceiling]

MAS uses same key for windows 10 and 11 pro, MAS chooses what key to use based on edition.

https://massgrave.dev/hwid.html#Supported_Products