ONLYOFFICE removes Power Query and Data Model metadata from XLSX after save

[morzazil]

This issue is unique.

• I have used the search tool and did not find an issue describing my bug.

Operating System of DocumentServer

Docker

Version information

9.1.0.168

Expected Behavior

Even if Power Query editing is unsupported, ONLYOFFICE should preserve unsupported XLSX/XML parts during save operations to avoid workbook corruption and metadata loss.

Actual Behavior

• Power Query queries disappear
• Workbook connections are removed
• Data Model metadata is lost

Reproduction Steps

1. Create an XLSX workbook in Microsoft Excel Desktop
2. Add one or more Power Query queries
3. Save the workbook
4. Upload it to Nextcloud
5. Open the file in ONLYOFFICE via browser
6. Save the file without making changes
7. Open the saved file again in Microsoft Excel Desktop

Additional information

XLSX files containing Power Query queries and Excel Data Model lose their queries and connections after being opened and saved in ONLYOFFICE.

Test Only office_before editing online.xlsx
Test Only office_after editing online.xlsx