fix: external knowledge setting in knowledge selector (#18519)

web/app/components/app/configuration/dataset-config/settings-modal/index.tsx

   const { notify } = useToastContext()
   const ref = useRef(null)
   const isExternal = currentDataset.provider === 'external'
-  const [topK, setTopK] = useState(currentDataset?.external_retrieval_model.top_k ?? 2)
-  const [scoreThreshold, setScoreThreshold] = useState(currentDataset?.external_retrieval_model.score_threshold ?? 0.5)
-  const [scoreThresholdEnabled, setScoreThresholdEnabled] = useState(currentDataset?.external_retrieval_model.score_threshold_enabled ?? false)
   const { setShowAccountSettingModal } = useModalContext()
   const [loading, setLoading] = useState(false)
   const { isCurrentWorkspaceDatasetOperator } = useAppContext()
   const [localeCurrentDataset, setLocaleCurrentDataset] = useState({ ...currentDataset })
+  const [topK, setTopK] = useState(localeCurrentDataset?.external_retrieval_model.top_k ?? 2)
+  const [scoreThreshold, setScoreThreshold] = useState(localeCurrentDataset?.external_retrieval_model.score_threshold ?? 0.5)
+  const [scoreThresholdEnabled, setScoreThresholdEnabled] = useState(localeCurrentDataset?.external_retrieval_model.score_threshold_enabled ?? false)
   const [selectedMemberIDs, setSelectedMemberIDs] = useState<string[]>(currentDataset.partial_member_list || [])
   const [memberList, setMemberList] = useState<Member[]>([])
 
       setScoreThreshold(data.score_threshold)
     if (data.score_threshold_enabled !== undefined)
       setScoreThresholdEnabled(data.score_threshold_enabled)
+
+    setLocaleCurrentDataset({
+      ...localeCurrentDataset,
+      external_retrieval_model: {
+        ...localeCurrentDataset?.external_retrieval_model,
+        ...data,
+      },
+    })
   }
 
   const handleSave = async () => {