Change from Pro to Pro N?

I have a problem, after moving to the AAD, we have a few Windows devices that were upgraded to Windows 11 Pro in advance for enrollment via autopilot, this was done at that time with the generic Pro key "3V66T", as there were no license keys yet (accounting problem etc.) Now we have bought Windows 11 Pro N licenses for the remaining devices, as we are a non-profit company...now of course these cannot be installed because the Windows edition does not match.

Is there any way to change the Windows edition from Pro to Pro N without a reinstallation or in-place upgrade?

According to our dealer, we can no longer return or convert the keys

kind regards