The Windows Server Hybrid Core Infrastructure materials explain that Windows Hello for Business (WHfB) in a hybrid environment relies on Azure AD registration and corresponding device objects in on-premises AD DS. Azure AD Connect provides the Device writeback optional feature, which "writes Azure AD device objects back to AD DS as msDS-Device objects so on-premises domain controllers and policies can recognize and evaluate the device during authentication." The guide further notes that for hybrid-joined Windows 10/11 devices, enabling Device writeback "allows on-premises authentication stacks and Conditional Access decisions to use the registered device and its key material (key trust or certificate trust), enabling WHfB sign- in on domain-joined devices." Other options do not meet the requirement: Password writeback is used for self- service password reset, Group writeback returns Microsoft 365 groups to AD DS, and Directory extension attribute sync simply synchronizes custom attributes. Therefore, to ensure users can sign in with Windows Hello for Business on Azure AD hybrid-joined devices, select Device writeback in Azure AD Connect.