diff --git a/api/orders/setLineItem.cfm b/api/orders/setLineItem.cfm
index 23a1dcf..407ce32 100644
--- a/api/orders/setLineItem.cfm
+++ b/api/orders/setLineItem.cfm
@@ -49,6 +49,20 @@
   </cfif>
   <cfset arrayAppend(request.attachDebug, "attachDefaultChildren: OrderID=#arguments.OrderID#, ParentLI=#arguments.ParentLineItemID#, ParentItemID=#arguments.ParentItemID#")>
 
+  <!--- Check if this parent is an inverted group — if so, skip auto-adding defaults.
+        Inverted groups have all children pre-selected by default, but the client
+        explicitly sends only the ones the user kept checked. Auto-adding would
+        re-add items the user unchecked. --->
+  <cfset var qParentInfo = queryTimed(
+    "SELECT IsInvertedGroup FROM Items WHERE ID = ? LIMIT 1",
+    [ { value = arguments.ParentItemID, cfsqltype = "cf_sql_integer" } ],
+    { datasource = "payfrit" }
+  )>
+  <cfif qParentInfo.recordCount GT 0 AND val(qParentInfo.IsInvertedGroup) EQ 1>
+    <cfset arrayAppend(request.attachDebug, "  -> SKIP inverted group ##" & arguments.ParentItemID & " (client sends selections explicitly)")>
+    <cfreturn>
+  </cfif>
+
   <!--- Find ALL immediate children (to recurse into groups) --->
   <cfset var qAllKids = queryTimed(
     "