Planned quantity is lower than issued quantity

In B1 10, FP2105HF1 I'm trying to updat an existing workorder done the ServiceLayer.

We already issues 18 pieces of 1 constituent and the planned qty is 18. When I update the WO done the servicelayer to little the planned qty to 9 I person this error:

Planned quantity is little than issued quantity [ProductionOrderLines.PlannedQuantity][line: 3]

But I don't privation to alteration the issues qty of enactment 3, it tin enactment similar that. I'm besides keeping the plannenqty connected enactment level astatine 18. How tin I alteration the plannedqty connected the header to 9?

This is my Json:

{
"AbsoluteEntry": 3094,
"DocumentNumber": 241723094,
"Series": 27,
"ItemNo": "PARC -13",
"ProductionOrderStatus": "boposReleased",
"ProductionOrderType": "bopotStandard",
"PlannedQuantity": 9,
"JournalRemarks": "Production Order - PARC -13",
"ProductDescription": "PARC13",
"Priority": 100,
"ProductionOrderLines": [
{
"DocumentAbsoluteEntry": 3094,
"LineNumber": 0,
"ItemNo": "W-PARC -13",
"BaseQuantity": 1.5,
"PlannedQuantity": 18,
"IssuedQuantity": 0,
"ProductionOrderIssueType": "im_Backflush",
"Warehouse": "04",
"VisualOrder": 0,
"ItemType": "pit_Item",
"AdditionalQuantity": 0,
"StartDate": "2024-07-03",
"EndDate": "2024-07-23",
"RequiredDays": 0
},
{
"DocumentAbsoluteEntry": 3094,
"LineNumber": 1,
"ItemNo": "UF 0054 40/10 PANA",
"BaseQuantity": 0.05,
"PlannedQuantity": 0.6,
"IssuedQuantity": 0,
"ProductionOrderIssueType": "im_Manual",
"Warehouse": "MAT PANA",
"VisualOrder": 1,
"ItemType": "pit_Item",
"AdditionalQuantity": 0,
"StartDate": "2024-07-03",
"EndDate": "2024-07-23",
"RequiredDays": 0
},
{
"DocumentAbsoluteEntry": 3094,
"LineNumber": 2,
"ItemNo": "C-PARC -13",
"BaseQuantity": 1.5,
"PlannedQuantity": 18,
"IssuedQuantity": 18,
"ProductionOrderIssueType": "im_Manual",
"Warehouse": "03",
"VisualOrder": 2,
"ItemType": "pit_Item",
"AdditionalQuantity": 0,
"StartDate": "2024-07-03",
"EndDate": "2024-07-23",
"RequiredDays": 0
},
{
"DocumentAbsoluteEntry": 3094,
"LineNumber": 3,
"ItemNo": "D-250F-UF-0054",
"BaseQuantity": 1.5,
"PlannedQuantity": 18,
"IssuedQuantity": 0,
"ProductionOrderIssueType": "im_Backflush",
"Warehouse": "03",
"VisualOrder": 3,
"ItemType": "pit_Item",
"AdditionalQuantity": 0,
"StartDate": "2024-07-03",
"EndDate": "2024-07-23",
"RequiredDays": 0
},
{
"DocumentAbsoluteEntry": 3094,
"LineNumber": 4,
"ItemNo": "E-250-UF-0054",
"BaseQuantity": 1.5,
"PlannedQuantity": 18,
"IssuedQuantity": 0,
"ProductionOrderIssueType": "im_Backflush",
"Warehouse": "03",
"VisualOrder": 4,
"ItemType": "pit_Item",
"AdditionalQuantity": 0,
"StartDate": "2024-07-03",
"EndDate": "2024-07-23",
"RequiredDays": 0
}
]
}