Running Macs, High Sierra, in a lab environment. Serving K-12 students. File sharing important as students drop off assignments (files) to instructor computer. However, students logged on to the Active Directory domain cannot drop off files in the instructor's public folder-->Drop Box. SMB and AFS sharing both enabled in System Prefs (sharing). Testing with local accounts on same computers, file sharing works (local account can drop off files) but AD user accounts cannot.