Troubleshooting BitLocker from the Microsoft Endpoint Manager admin center

David Beck The group policy conflicts are almost certainly caused by conflicting settings in the startup authentication settings, either set these all to allow or set the compatible TPM startup to required and the rest to block (more about this in an upcoming blog).

I would strongly recommend using the endpoint protection rather than device config because all the new features will be added here and not device config. 

Also make sure you dont have conflicting policies deployed which may cause confusion about what settings are being applied.