Power BI Refresh Overwrites Correct Data With Old Version

I’m running into a strange Power BI Service behavior that I can’t explain.

• I have a report that pulls data from a SharePoint Online Excel file.

• When I publish a fresh copy of the PBIX to any workspace (including My Workspace), the data is correct.

• As long as I don’t refresh the dataset in the Service, the report continues to show the correct data.

• The moment I trigger a manual refresh or a scheduled/automatic refresh runs, the dataset instantly reverts to old/bad data.

• The refresh completes in just a few seconds, which is unusually fast for a SharePoint source.

• After the refresh, the report “flashes” the correct data for a moment, then snaps back to the old data.

• This happens even if I:

  • delete the dataset

  • republish the PBIX under a new name

  • create a brand‑new copy of the PBIX

  • publish to a different workspace

  • reconnect the SharePoint source

  • verify the file ID is correct

• The same behavior occurs in My Workspace, which rules out lineage, pipelines, shared datasets, or workspace‑level overrides.

• I am connecting to the data source via Personal Cloud Connect (OAuth & Organizational)
• There are no bookmarks or filters

I’m trying to understand why Power BI Service is reverting to outdated data after refresh, even though Desktop and the published dataset initially show the correct values.