Has anyone run into a bug with the Demand Planning MRP Workbench, where a safety stock was set to a specific location a while ago with that has no current inventory, and now the Workbench keep re-generating duplicated Planned PO/TO/WOs to fulfil that safety stock over and over, even though the relevant Planned Transactions have already been converted to Approved PO/TO/WOs?

Have you set the Late Period days on the item master location level?