Azure AD Sync Service failed to start due to a logon failure

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We receive a call from our client saying that the new user created in AD is NOT synced to Office 365 this morning, and we noticed that the Microsoft Azure AD Sync failed to start due to logon failure

The Azure AD Account (AAD_7b1a020a031e) which is the local user account configured as Password Never Expired and we do not think this is the issue related with password expired

The root cause of this issue is due to the local GPO for “Login on as Service” was overrived by the Domain GPO and accidentlly removed Azure AD Service Account. Once we removed the Domain GPO and added the Azure AD Service Account in the local GPO, the Azure AD Service is started successfully now

#Start ADSync Service
Get-Service | ? name -eq "ADSync" | Start-Service

#Perform Manual Full / Delta Sync 
Import-Module ADSync
Start-ADSyncSyncCycle  -PolicyType  Initial
Start-ADSyncSyncCycle -PolicyType Delta