Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
The following resolved this issue for us (solution provided by Microsoft support):
Go to portal.azure.com > Microsoft Entra ID > Mobility (MDM and WIP) > Microsoft Intune
Set "Windows Information Protection (WIP) user scope" to "None"
Since we were not using any WIP policies, this had no functional impact to us, other than resolving the enrollment issue.