diff --git a/ui/src/views/Forecast.jsx b/ui/src/views/Forecast.jsx
index 6b726e1..d8f3745 100644
--- a/ui/src/views/Forecast.jsx
+++ b/ui/src/views/Forecast.jsx
@@ -1098,12 +1098,18 @@ export default function Forecast({ sources = [], sourceId, versions = [], versio
       if (!res.ok) return
       derived = await res.json()
     }
-    if (!derived) return
+    if (!derived) {
+      flash(`No attributes found for ${col} "${value.trim()}" — the other fields are unchanged`, 'warn')
+      return
+    }
+
+    // Overwrite rather than only filling blanks. These columns describe the key
+    // that was just entered, so whatever a previous key left behind is wrong, not
+    // worth preserving -- and leaving it made a second lookup look like it had
+    // done nothing at all, since every box was already full.
     setter(prev => {
       const next = { ...prev }
-      for (const [k, v] of Object.entries(derived)) {
-        if (!prev[k] || prev[k] === '') next[k] = String(v ?? '')
-      }
+      for (const [k, v] of Object.entries(derived)) next[k] = String(v ?? '')
       return next
     })
   }