If you want to upgrade AD Connect v1.1.380.0 to the latest version (1.1.443.0) follow the below steps:
Open Azure AD Connect
Will apear the wizard where you need to accept EULA. Push on Continue.
Wizard will notify you that you will upgrade AD Connect. Push on upgrade button.
On the Connect to Azure AD step insert a Global Admin user an push on Next.
On the Connect to AD DS section indicate a Domain Admin and push Next.
Once on the Configure Step select Start the sync process when configuration completes and push Upgrade.
A few minutes the upgrade will finish. Push Exit.
To purge deleted users you have to run the following syntax using Azure Powershell cmdlets:
List deleted users:
Purge deleted users:
Remove-MsolUser -UserPrincipalName firstname.lastname@example.org -RemoveFromRecycleBin
A few days ago, someone deleted users in Azure with the following comand:
Get-MsolUser -UserPrincipalName SEPR0002@domain.com | remove-msoluser
Automatically, AD Connect has started to say that an object is phantom.
The problem has been fixed automatically 24 hours after.
Below I put an imprescindible link from the pfe blog talking about Azure Active Directory (AAD).