We tackle these by making sure the reset went through, checking Azure AD Connect, and confirming each device uses the right sign-in setup. We keep password synchronization reliable by staying proactive and making sure users know how their actions affect access across Microsoft 365 and their devices. Even when sync works, cached passwords on devices can cause login failures. Windows, Outlook, and mobile apps often save passwords so users don’t have to keep typing them. If a password changes, those caches might still use the old one until you clear them out. The M365 sync establishes a synced dataset based on your M365 data and the filtering configuration of your sync.

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Outdated credentials get stuck on devices, password sync gets turned off, or Microsoft Entra Connect just doesn’t update like it should. Here’s a step-by-step approach to help you spot the issue, fix it, and avoid these sync delays down the road. While M365 is highly stable, it’s not immune to occasional disruptions. We also check the synchronization scheduler to confirm delta and full sync cycles finish successfully.

What to do when Office 365 password reset doesn’t sync across devices

On Windows, open Credential Manager, pick Windows Credentials, and remove anything related to Office 365 or Microsoft 365. On macOS or iOS, delete stored credentials from Keychain Access. To update from Azure AD Sync fix Outlook after Windows update issues to Microsoft Entra Connect, see the upgrade instructions.

Login & Sync Errors: Personal & Business Microsoft 365 Accounts on Same Device

Azure AD Connect handles password sync, but it runs on a schedule—usually every 30 minutes. So, if you just changed your password, there might be a short window where your old password still works and the new one hasn’t reached every system. At NetTech Consultants, we help organizations keep Microsoft 365 running smoothly and securely. We go above and beyond the average software reseller because we built our business on trust. As active members in the IT community, we work to support our clients’ businesses and provide them with peace of mind.

Reviewing Device Sign-In Settings

The Summary sheet on the spreadsheet attachment of your sync summary includes an Updated User Count and User Limit. These figures will give you an impression of how far over the limit the account is. Sync failure alerts do not always include a full summary or Fix Outlook and Office365 Sync Issues attachment, you can run a test sync to obtain this data.



Password sync usually fails when credentials don’t update between Microsoft Entra ID (Azure AD) and your on-premises Active Directory. Most of the time, the problem comes from timing delays, configuration mistakes, or cached credentials on devices that don’t pick up new passwords. We check that Microsoft Entra Connect (Azure AD Connect) runs the latest version and password sync is on. Keeping things updated helps avoid compatibility issues between on-premises Active Directory and Microsoft 365. If problems stick around, we rejoin the flush DNS and re-sync Outlook devices to Microsoft 365 services.

Common Causes of Office 365 Password Reset Sync Issues

• If problems stick around, we rejoin the devices to Microsoft 365 services.
• Even I've only been doing this with test users so far, so haven't actually broken any actual users yet, I still need to get this resolved quickly.
• We also scan Event Viewer logs under Applications and Services Logs → Directory Synchronization for Event IDs like 650–657 (for sync activity).
• Running the Azure AD Connect Health tool gives you alerts for sync errors and interruptions.
• We also check the synchronization scheduler to confirm delta and full sync cycles finish successfully.
• You can stop any accounts from being brought over by adding them to the sync deny list.
• Users I create within the Office 365 portal are fine, so I assume it is something to do with Azure AD Connect.

You should run a test sync after re-authenticating the sync to ensure it is working. Devices sometimes keep using cached passwords even after a successful sync. If users access multiple apps with the same login, we make sure Single Sign-On (SSO) settings line up so the new password works everywhere in Microsoft 365. If there’s a delay, we manually trigger a password sync using Microsoft Entra Connect.