Hi,
Try following steps in Dev first before it applies to Production.
1. Make a on-hand qty to zero. (Across all sites and warehouses. No physical, financial, or reserved quantity)
2. Ensure the item isn’t used in any open purchase/sales orders, journals, BOMs, or trade agreements
3. Run Inventory closing
4. Try Changing the Storage/Tracking Dimension Groups
This should work for your case.