OneDrive Known Folder Backup fails with "We’re having trouble connecting to the OneDrive service" after clean Windows reinstall

(This is a Portuguese forum, but I noticed that you originally posted your question in English, so please allow me to reply in English to make the discussion easier for you. Thank you very much for your understanding.)

Hi @Anderson Sampaio,

Thank you for taking the time to provide such a detailed description of the issue, along with the extensive troubleshooting steps you've already performed.

From what you've shared, it looks like you've done a very thorough job investigating the problem and have already ruled out many of the common client-side causes. The fact that the same behavior persists even after a clean Windows installation makes this particularly interesting, as it suggests the issue may involve factors beyond the local device itself.

As this is a community forum, I'm somewhat limited in terms of the tools and visibility available to me. I don't have access to your tenant's backend configuration, service telemetry, or the diagnostic data needed to determine exactly where the sync process is breaking down. For that reason, I'm afraid I can't directly verify whether the issue is related to provisioning, policy configuration, licensing, synchronization restrictions, or another service-side component.

Given the extensive troubleshooting you've already completed, I believe the most appropriate next step would be to open a support ticket through your Microsoft 365 Admin Center: Get support - Microsoft 365 admin | Microsoft Learn (If you are not a Microsoft 365 administrator, you may need to contact your Microsoft 365 admin and ask them to create the support request on your behalf.)

Tips: You can switch off the Support Assistant as shown in the screenshot, then type a few short characters into the search box and select Get Help. After that, wait for the Contact Support button to appear and click it. At the final step, be sure to clearly describe your request in the description fields so the support engineers can quickly understand your issue and assist you more effectively. 

Once the ticket is opened, a Microsoft support engineer can conduct a remote session to investigate the issue in greater depth. They will be able to collect and analyze OneDrive sync logs, review tenant-side telemetry, validate licensing and provisioning status, inspect SharePoint Online and OneDrive backend configurations, and verify whether any Conditional Access policies, Intune configurations, Known Folder Move policies, or synchronization restrictions may be contributing to the behavior.

If necessary, they can also escalate the case to a specialized engineering team for deeper analysis and assistance in identifying and resolving the underlying issue.

I hope this points you toward a more effective path forward and ultimately saves you valuable time, as the support team will have access to the backend data and diagnostic capabilities needed to properly investigate this scenario.

I wish you the very best with the investigation.

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