WS 2022 ADDS / Entra ID Sync

Hello,

We installed Azure AD Connect to synchronize our AD with our tenant acme.onmicrosoft.com.

The synchronization account has been created successfully, on our tenant. More generally,
an account created on the AD goes back to Entra ID.

But not the opposite: none of the existing or subsequently created accounts on the tenant are replicated on the AD: Why?

thanks in advance

L.