My ramblings on the stuff that holds it all together
No recent password sync error shown in Office365 portal but Directory synchronization is ok
I ran into this, my dirsync was running ok (new objects copied out from on-prem AD to AAD ok) but password changes on-prem were not going out.
Weird, wasn’t related to this post as no recent password change of the admin account used in the lab.
I can highly recommend using the built-in PowerShell diagnostics tool on your AAD Sync server – just run it by using Invoke-ADSyncDiagnostics in a PowerShell session and follow the prompts.. in my case, it discovered the the password hash sync service wasn’t running, script restarted it.
Not sure if this was some hiccup due to me recently enabling password write-back and some MFA config. but it fixed it for me.