Hello @Ádám Gulyás
Thank you for Reaching Out Microsoft Q&A platform.
I understand that in your organization some IT admin has only "User admin" role and in that case, they cannot see the synchronization status with on-prem AD.
The "Hybrid Identity Administrator" role could indeed grant the necessary access to manage and view directory synchronization.
The Hybrid Identity Administrator role is specifically designed for managing and viewing Azure AD Connect synchronization status and related tasks. It grants permissions to manage Azure AD Connect, monitor synchronization status, and handle hybrid identity configurations. This role is more appropriate for the specific use case of granting IT admins access to sync status
For additional information refer this document: https://learn.microsoft.com/en-us/entra/identity/role-based-access-control/permissions-reference#hybrid-identity-administrator
As mentioned, when creating custom roles, the permissions associated with privileged roles cannot be customized.
Hope this helps. Do let us know if you any further queries.