This is how to Force AD to Sync with Office 365. By Default, Active directory synchronisation happens every 30 minutes and it runs on the Server you Installed Azure AD on.
To start a manual sync, Log In to the Server you’ve Installed Azure AD Sync and open PowerShell.
In the PowerShell windows type the cmdlet below:
Start-ADSyncSyncCycle -PolicyType Delta
The cmdlet lets will start a delta synchronisation which will sync all the changes that were made In Active Directory since the last sync.
It Important to note that a manual sync doesn’t sync password.
Password sync will run every 30 minutes as well.