Hi,
Thank you for providing the detailed information and for documenting the troubleshooting steps you have already completed.
Based on the behavior you described, especially since the same issue occurs with multiple personal Microsoft accounts and persists after reinstalling Power Automate Desktop and clearing the local authentication-related caches, this does not appear to be an issue specific to a single Microsoft account.
One important consideration is that Power Automate Desktop sign-in and cloud integration are primarily designed around organizational or school accounts with the appropriate Power Automate/Power Platform services available. A personal Microsoft account without a Microsoft 365 or organizational Power Platform environment may encounter limitations with authentication or the cloud services that Power Automate Desktop attempts to access during sign-in.
The fact that OneDrive itself is working normally for uploading, downloading, and editing files also suggests that the error message may not indicate a general OneDrive storage problem. Instead, the failure could be occurring when Power Automate Desktop attempts to initialize or access a dependent cloud service during the authentication process.
Since you have already completed the primary local troubleshooting steps, I would recommend the following:
1. If available, test Power Automate Desktop using a work or school Microsoft account that has access to Power Automate.
2. Confirm whether the issue occurs only when using personal Microsoft accounts.
3. If the issue continues with a properly licensed work or school account, the Correlation ID and the approximate date/time of the failed sign-in should be provided to Microsoft Support so they can investigate the corresponding service-side authentication logs.
Because the same Correlation ID is being returned after the local troubleshooting you performed, further deletion of Windows credentials or authentication caches is unlikely to provide additional value at this stage.
If this is specifically a personal Microsoft account scenario, I would first validate whether the account type is supported for the Power Automate Desktop functionality you are attempting to use before treating this as a OneDrive account corruption issue.
I hope this helps clarify the next steps.
Thanks & Regards,
Manoj Annavajjala