This appears to be a new issue that I am experiencing. In Fall we bought 200 Dell 5410 laptops. We were able to image the devices through SCCM and they also appear in Intune as well.
Now, 9 months later, we are trying to deploy new devices (Dell OptiPlex 7780 AIO) devices. I am getting an error message, "Registering your device for mobile management Failed: 6, 0x8018000a). From what I have read it's an issue with SCCM and Intune.