diff --git a/src/hooks/useHashrateHistory.ts b/src/hooks/useHashrateHistory.ts
index a44060b..5bd6a91 100644
--- a/src/hooks/useHashrateHistory.ts
+++ b/src/hooks/useHashrateHistory.ts
@@ -18,41 +18,40 @@ const SAMPLE_INTERVAL_MS = 5000; // Sample every 5 seconds
  */
 export function useHashrateHistory(currentHashrate: number | undefined): HashrateDataPoint[] {
   const [history, setHistory] = useState<HashrateDataPoint[]>([]);
-  const lastSampleTime = useRef<number>(0);
+  const hashrateRef = useRef<number | undefined>(currentHashrate);
 
+  // Keep ref in sync with latest value without triggering the interval effect
   useEffect(() => {
-    if (currentHashrate === undefined || currentHashrate === null) return;
+    hashrateRef.current = currentHashrate;
+  }, [currentHashrate]);
 
-    const now = Date.now();
-    
-    // Only add a new sample if enough time has passed
-    if (now - lastSampleTime.current < SAMPLE_INTERVAL_MS) return;
-    
-    lastSampleTime.current = now;
-    
-    const timeStr = new Date(now).toLocaleTimeString('en-US', {
-      hour: '2-digit',
-      minute: '2-digit',
-      hour12: false,
-    });
+  // Sample on a fixed interval regardless of whether the value changed.
+  // Previously this used useEffect([currentHashrate]) which only fired on
+  // value changes — meaning a constant hashrate (including 0) would never
+  // accumulate more than one data point and the chart would stay blank.
+  useEffect(() => {
+    function sample() {
+      const value = hashrateRef.current;
+      if (value === undefined || value === null) return;
 
-    setHistory(prev => {
-      const newPoint: HashrateDataPoint = {
-        time: timeStr,
-        timestamp: now,
-        hashrate: currentHashrate,
-      };
-      
-      const updated = [...prev, newPoint];
-      
-      // Keep only the last MAX_HISTORY_POINTS
-      if (updated.length > MAX_HISTORY_POINTS) {
-        return updated.slice(-MAX_HISTORY_POINTS);
-      }
-      
-      return updated;
-    });
-  }, [currentHashrate]);
+      const now = Date.now();
+      const timeStr = new Date(now).toLocaleTimeString('en-US', {
+        hour: '2-digit',
+        minute: '2-digit',
+        hour12: false,
+      });
+
+      setHistory(prev => {
+        const newPoint: HashrateDataPoint = { time: timeStr, timestamp: now, hashrate: value };
+        const updated = [...prev, newPoint];
+        return updated.length > MAX_HISTORY_POINTS ? updated.slice(-MAX_HISTORY_POINTS) : updated;
+      });
+    }
+
+    sample(); // Capture initial value immediately
+    const id = setInterval(sample, SAMPLE_INTERVAL_MS);
+    return () => clearInterval(id);
+  }, []); // Run once on mount
 
   return history;
 }
diff --git a/src/pages/Settings.tsx b/src/pages/Settings.tsx
index 8374562..237328c 100644
--- a/src/pages/Settings.tsx
+++ b/src/pages/Settings.tsx
@@ -83,11 +83,6 @@ export function Settings({ appMode = 'translator' }: SettingsProps) {
               View connection status, endpoints, and API documentation.
             </p>
           </div>
-          <div className="flex items-center space-x-2">
-            <Button variant="outline" onClick={() => window.location.reload()}>
-              Refresh Status
-            </Button>
-          </div>
         </div>
 
         <Tabs defaultValue="status" className="space-y-6">
diff --git a/src/pages/UnifiedDashboard.tsx b/src/pages/UnifiedDashboard.tsx
index c2cf8dd..5767b69 100644
--- a/src/pages/UnifiedDashboard.tsx
+++ b/src/pages/UnifiedDashboard.tsx
@@ -1,5 +1,5 @@
 import { useState, useMemo } from 'react';
-import { AlertTriangle, Search, RefreshCw } from 'lucide-react';
+import { AlertTriangle, Search } from 'lucide-react';
 import { Shell } from '@/components/layout/Shell';
 import { StatCard } from '@/components/data/StatCard';
 import { HashrateChart } from '@/components/data/HashrateChart';
@@ -50,7 +50,6 @@ export function UnifiedDashboard() {
   const {
     data: sv1Data,
     isLoading: sv1Loading,
-    refetch: refetchSv1,
   } = useSv1ClientsData(0, 1000); // Fetch all for client-side filtering
 
   const {
@@ -86,12 +85,26 @@ export function UnifiedDashboard() {
     return allClients.reduce((sum, c) => sum + (c.hashrate || 0), 0);
   }, [allClients]);
 
-  // Total hashrate:
-  // - JD mode: from SV2 client channels (poolGlobal.sv2_clients.total_hashrate)
-  // - Translator-only mode: from SV1 clients (poolGlobal.sv1_clients.total_hashrate or calculated)
-  const totalHashrate = isJdMode 
-    ? (poolGlobal?.sv2_clients?.total_hashrate || 0)
-    : (poolGlobal?.sv1_clients?.total_hashrate || sv1TotalHashrate);
+  // Sum nominal hashrates from downstream client channels (JD mode fallback)
+  const clientChannelHashrate = useMemo(() => {
+    if (!clientChannels) return undefined;
+    const ext = clientChannels.extended_channels.reduce((sum, ch) => sum + (ch.nominal_hashrate || 0), 0);
+    const std = clientChannels.standard_channels.reduce((sum, ch) => sum + (ch.nominal_hashrate || 0), 0);
+    return ext + std;
+  }, [clientChannels]);
+
+  // Total hashrate, with multiple fallback sources:
+  // - JD mode: sv2_clients summary → client channel nominal hashrates
+  // - Translator-only mode: sv1_clients summary → individual client sum → server reported total
+  // Use nullish coalescing so an explicit 0 hashrate is preserved.
+  const totalHashrate = isJdMode
+    ? (poolGlobal?.sv2_clients?.total_hashrate ?? clientChannelHashrate ?? 0)
+    : (
+      poolGlobal?.sv1_clients?.total_hashrate
+      ?? (sv1Data ? sv1TotalHashrate : undefined)
+      ?? poolGlobal?.server?.total_hashrate
+      ?? 0
+    );
 
   const totalClientChannels = isJdMode 
     ? (poolGlobal?.sv2_clients?.total_channels || 0)
@@ -281,15 +294,6 @@ export function UnifiedDashboard() {
               </div>
             </div>
 
-            <div className="flex items-center gap-2 w-full sm:w-auto justify-end">
-              <button
-                onClick={() => refetchSv1()}
-                className="h-9 px-3 rounded-lg border border-border/50 bg-muted/30 hover:bg-background transition-colors flex items-center gap-2 text-sm"
-              >
-                <RefreshCw className="h-4 w-4" />
-                Refresh
-              </button>
-            </div>
           </div>
         </div>
       )}