diff --git a/apps/web/src/components/reui-kit/uptime-chart.test.ts b/apps/web/src/components/reui-kit/uptime-chart.test.ts
index b7e9155..f204ac5 100644
--- a/apps/web/src/components/reui-kit/uptime-chart.test.ts
+++ b/apps/web/src/components/reui-kit/uptime-chart.test.ts
@@ -45,6 +45,28 @@ describe('toAlignedSeries', () => {
     expect(keys).toEqual(['local', 'cloudflare', 'globalping'])
   })
 
+  it('keeps live latency when another IP in the same bucket is down', () => {
+    const { points } = toAlignedSeries([
+      probe({
+        id: 1,
+        latency_ms: 18,
+        checked_at: '2026-01-01T00:00:10.000Z',
+      }),
+      probe({
+        id: 2,
+        status: 'down',
+        ok: false,
+        latency_ms: null,
+        checked_at: '2026-01-01T00:00:12.000Z',
+      }),
+    ])
+
+    expect(points).toHaveLength(1)
+    expect(points[0]?.local).toBe(18)
+    expect(points[0]?.localOk).toBe(true)
+    expect(points[0]?.ok).toBe(true)
+  })
+
   it('does not plot down probes as latency 0', () => {
     const { points } = toAlignedSeries([
       probe({
diff --git a/apps/web/src/components/reui-kit/uptime-chart.tsx b/apps/web/src/components/reui-kit/uptime-chart.tsx
index 293b4cd..126a76e 100644
--- a/apps/web/src/components/reui-kit/uptime-chart.tsx
+++ b/apps/web/src/components/reui-kit/uptime-chart.tsx
@@ -124,8 +124,13 @@ export function toAlignedSeries(items: UptimeProbe[]): {
     }
 
     const ok = probeOk(item)
-    row[`${key}Ok`] = ok
-    row[key] = ok ? item.latency_ms : null
+    const prevOk = row[`${key}Ok`]
+    row[`${key}Ok`] = prevOk === true || ok
+    if (ok && item.latency_ms != null) {
+      row[key] = item.latency_ms
+    } else if (row[key] === undefined) {
+      row[key] = null
+    }
   }
 
   const points = [...buckets.entries()]