diff --git a/ui/src/pages/ProductionProductCostingHasCostDetail.vue b/ui/src/pages/ProductionProductCostingHasCostDetail.vue
index 29e8e83..c2de28b 100644
--- a/ui/src/pages/ProductionProductCostingHasCostDetail.vue
+++ b/ui/src/pages/ProductionProductCostingHasCostDetail.vue
@@ -2901,8 +2901,10 @@ function shouldIncludeRowInGroupTotal (grp, row) {
 }
 
 function rowsForGroupTotal (grp) {
-  const groupName = normalizeGroupName(grp?.sAciklama3)
-  return flatDetailRows.value.filter(row => normalizeGroupName(row?.sAciklama3) === groupName)
+  // Use the exact row collection rendered by the QTable under this header.
+  // The flattened list can temporarily hold stale row objects during QTable
+  // inline edits and bulk replacements.
+  return Array.isArray(grp?.items) ? grp.items : []
 }
 
 function resolveGroupIncludedCount (grp) {