We setup DEP and preStage successfully. preStage enrollment requires Active Directory credentials, which we verified to be working before enrolling. The Active Direcotry login populates the local user information (e.g. First, Last name along with uid) correctly. The local account is created correctly, and when it loads, the managementFramework enrollment is not fully complete. In JSS, the computer status ends up in an 'unmanaged' state.
Conversely, when using the QuickAdd.pkg (downloaded from user-initiated enrollment page) with the same login credentials, we observe that the enrollment is fully successful and the computer is Managed by the Management Account. We have reproduced the same issue on multiple computers with multiple user credentials to rule out any potential anomalies. Additionally, we have verified the JSS hosts are able to communicate with APNS, HTTPS, etc.