diff --git a/ui/src/components/Sidebar.tsx b/ui/src/components/Sidebar.tsx
index 613baa6278..429ca9c42b 100644
--- a/ui/src/components/Sidebar.tsx
+++ b/ui/src/components/Sidebar.tsx
@@ -68,7 +68,10 @@ export function Sidebar() {
     resourceKey: "live-runs",
     queryKey: liveRunsQueryKey,
     enabled: !!selectedCompanyId,
-    refetchInterval: 10_000,
+    // Event-sourced via LiveUpdatesProvider (#9627) + reconnect reconcile — no
+    // interval poll needed. Polling here also re-armed React Query's timer on
+    // every live-event cache write, a major source of steady-state churn.
+    refetchInterval: false,
     leaderOnly: true,
   });
   const { data: liveRuns, dataUpdatedAt: liveRunsUpdatedAt } = useQuery({
diff --git a/ui/src/components/SidebarAgents.test.tsx b/ui/src/components/SidebarAgents.test.tsx
index 1cdfdd49a8..3ee1aeea3b 100644
--- a/ui/src/components/SidebarAgents.test.tsx
+++ b/ui/src/components/SidebarAgents.test.tsx
@@ -702,7 +702,8 @@ describe("SidebarAgents", () => {
     expect(agentLinkLabels(container)).toEqual(["Alpha"]);
 
     await act(async () => {
-      await vi.advanceTimersByTimeAsync(1);
+      await vi.advanceTimersByTimeAsync(5);
+      await vi.advanceTimersByTimeAsync(0);
     });
     expect(agentLinkLabels(container)).toEqual(["Alpha", "Bravo", "Charlie"]);
   });
@@ -758,12 +759,14 @@ describe("SidebarAgents", () => {
     expect(agentLinkLabels(container)).toEqual(["Alpha", "Bravo"]);
 
     await act(async () => {
-      await vi.advanceTimersByTimeAsync(60_001);
+      await vi.advanceTimersByTimeAsync(60_005);
+      await vi.advanceTimersByTimeAsync(0);
     });
     expect(agentLinkLabels(container)).toEqual(["Bravo"]);
 
     await act(async () => {
-      await vi.advanceTimersByTimeAsync(60_000);
+      await vi.advanceTimersByTimeAsync(60_005);
+      await vi.advanceTimersByTimeAsync(0);
     });
     expect(agentLinkLabels(container)).toEqual(["Alpha", "Bravo", "Charlie"]);
   });
diff --git a/ui/src/components/SidebarAgents.tsx b/ui/src/components/SidebarAgents.tsx
index da1f9dde4f..b344364d2f 100644
--- a/ui/src/components/SidebarAgents.tsx
+++ b/ui/src/components/SidebarAgents.tsx
@@ -339,7 +339,8 @@ export function SidebarAgents({ streamlined = false }: { streamlined?: boolean }
     resourceKey: "live-runs",
     queryKey: liveRunsQueryKey,
     enabled: !!selectedCompanyId,
-    refetchInterval: 10_000,
+    // Event-sourced via LiveUpdatesProvider (#9627); no interval poll needed.
+    refetchInterval: false,
     leaderOnly: true,
   });
   const { data: liveRuns, dataUpdatedAt: liveRunsUpdatedAt } = useQuery({
diff --git a/ui/src/pages/ExecutionWorkspaceDetail.tsx b/ui/src/pages/ExecutionWorkspaceDetail.tsx
index e130cf1b21..c2cac0b629 100644
--- a/ui/src/pages/ExecutionWorkspaceDetail.tsx
+++ b/ui/src/pages/ExecutionWorkspaceDetail.tsx
@@ -445,7 +445,8 @@ function ExecutionWorkspaceIssuesList({
     resourceKey: "live-runs",
     queryKey: liveRunsQueryKey,
     enabled: !!companyId,
-    refetchInterval: 5000,
+    // Event-sourced via LiveUpdatesProvider (#9627); no interval poll needed.
+    refetchInterval: false,
     leaderOnly: true,
   });
   const { data: liveRuns, dataUpdatedAt: liveRunsUpdatedAt } = useQuery({
diff --git a/ui/src/pages/Inbox.tsx b/ui/src/pages/Inbox.tsx
index f3ff80fe12..16355d1f5e 100644
--- a/ui/src/pages/Inbox.tsx
+++ b/ui/src/pages/Inbox.tsx
@@ -2,7 +2,6 @@ import { type ReactNode, useCallback, useEffect, useMemo, useRef, useState } fro
 import { Link, useLocation, useNavigate } from "@/lib/router";
 import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
 import { deriveOriginatingActor, INBOX_MINE_ISSUE_STATUS_FILTER } from "@paperclipai/shared";
-import { useVisibilityRefetchInterval } from "@/lib/polling";
 import { usePublishSharedQueryData, useSharedPollingQuery } from "@/hooks/useSharedPolling";
 import { approvalsApi } from "../api/approvals";
 import { accessApi } from "../api/access";
@@ -917,14 +916,14 @@ export function Inbox() {
     refetchOnWindowFocus: false,
     staleTime: INBOX_HOT_PATH_STALE_MS,
   });
-  const liveRunsRefetchInterval = useVisibilityRefetchInterval({ visibleMs: 5000 });
   const liveRunsQueryKey = queryKeys.liveRuns(selectedCompanyId!);
   const sharedLiveRuns = useSharedPollingQuery({
     companyId: selectedCompanyId,
     resourceKey: "live-runs",
     queryKey: liveRunsQueryKey,
     enabled: !!selectedCompanyId,
-    refetchInterval: liveRunsRefetchInterval,
+    // Event-sourced via LiveUpdatesProvider (#9627); no interval poll needed.
+    refetchInterval: false,
     leaderOnly: true,
   });
   const { data: liveRuns, dataUpdatedAt: liveRunsUpdatedAt } = useQuery({
diff --git a/ui/src/pages/IssueDetail.tsx b/ui/src/pages/IssueDetail.tsx
index 694fd42a70..acfc5ea85a 100644
--- a/ui/src/pages/IssueDetail.tsx
+++ b/ui/src/pages/IssueDetail.tsx
@@ -2,7 +2,6 @@ import { memo, useCallback, useEffect, useMemo, useRef, useState, type ChangeEve
 import { pickTextColorForPillBg } from "@/lib/color-contrast";
 import { Link, useLocation, useNavigate, useNavigationType, useParams } from "@/lib/router";
 import { useInfiniteQuery, useQuery, useMutation, useQueryClient, type InfiniteData, type QueryClient } from "@tanstack/react-query";
-import { useVisibilityRefetchInterval } from "@/lib/polling";
 import { usePublishSharedQueryData, useSharedPollingQuery } from "@/hooks/useSharedPolling";
 import { ApiError } from "../api/client";
 import { issuesApi } from "../api/issues";
@@ -1684,14 +1683,14 @@ export function IssueDetail() {
     queryFn: () => issuesApi.list(resolvedCompanyId!, { parentId: issue!.parentId!, includeBlockedBy: true }),
     enabled: !!resolvedCompanyId && !!issue?.parentId,
   });
-  const companyLiveRunsRefetchInterval = useVisibilityRefetchInterval({ visibleMs: 5000 });
   const companyLiveRunsQueryKey = resolvedCompanyId ? queryKeys.liveRuns(resolvedCompanyId) : ["live-runs", "pending"] as const;
   const sharedCompanyLiveRuns = useSharedPollingQuery<LiveRunForIssue[]>({
     companyId: resolvedCompanyId,
     resourceKey: "live-runs",
     queryKey: companyLiveRunsQueryKey,
     enabled: !!resolvedCompanyId,
-    refetchInterval: companyLiveRunsRefetchInterval,
+    // Event-sourced via LiveUpdatesProvider (#9627); no interval poll needed.
+    refetchInterval: false,
     leaderOnly: true,
   });
   const { data: companyLiveRuns, dataUpdatedAt: companyLiveRunsUpdatedAt } = useQuery({
diff --git a/ui/src/pages/Issues.tsx b/ui/src/pages/Issues.tsx
index c523e6edfa..97e367c0e7 100644
--- a/ui/src/pages/Issues.tsx
+++ b/ui/src/pages/Issues.tsx
@@ -8,7 +8,6 @@ import { heartbeatsApi } from "../api/heartbeats";
 import { useCompany } from "../context/CompanyContext";
 import { useBreadcrumbs } from "../context/BreadcrumbContext";
 import { collectLiveIssueIds } from "../lib/liveIssueIds";
-import { useVisibilityRefetchInterval } from "@/lib/polling";
 import { usePublishSharedQueryData, useSharedPollingQuery } from "@/hooks/useSharedPolling";
 import { queryKeys } from "../lib/queryKeys";
 import { createIssueDetailLocationState } from "../lib/issueDetailBreadcrumb";
@@ -98,14 +97,14 @@ export function Issues() {
     enabled: !!selectedCompanyId,
   });
 
-  const liveRunsRefetchInterval = useVisibilityRefetchInterval({ visibleMs: 5000 });
   const liveRunsQueryKey = queryKeys.liveRuns(selectedCompanyId!);
   const sharedLiveRuns = useSharedPollingQuery({
     companyId: selectedCompanyId,
     resourceKey: "live-runs",
     queryKey: liveRunsQueryKey,
     enabled: !!selectedCompanyId,
-    refetchInterval: liveRunsRefetchInterval,
+    // Event-sourced via LiveUpdatesProvider (#9627); no interval poll needed.
+    refetchInterval: false,
     leaderOnly: true,
   });
   const { data: liveRuns, dataUpdatedAt: liveRunsUpdatedAt } = useQuery({
diff --git a/ui/src/pages/ProjectDetail.tsx b/ui/src/pages/ProjectDetail.tsx
index 1c9b881bfd..b5bbcd03c2 100644
--- a/ui/src/pages/ProjectDetail.tsx
+++ b/ui/src/pages/ProjectDetail.tsx
@@ -241,7 +241,8 @@ function ProjectIssuesList({ projectId, companyId }: { projectId: string; compan
     resourceKey: "live-runs",
     queryKey: liveRunsQueryKey,
     enabled: !!companyId,
-    refetchInterval: 5000,
+    // Event-sourced via LiveUpdatesProvider (#9627); no interval poll needed.
+    refetchInterval: false,
     leaderOnly: true,
   });
   const { data: liveRuns, dataUpdatedAt: liveRunsUpdatedAt } = useQuery({
@@ -317,7 +318,8 @@ function ProjectPluginOperationsList({
     resourceKey: "live-runs",
     queryKey: liveRunsQueryKey,
     enabled: !!companyId,
-    refetchInterval: 5000,
+    // Event-sourced via LiveUpdatesProvider (#9627); no interval poll needed.
+    refetchInterval: false,
     leaderOnly: true,
   });
   const { data: liveRuns, dataUpdatedAt: liveRunsUpdatedAt } = useQuery({
diff --git a/ui/src/pages/Routines.tsx b/ui/src/pages/Routines.tsx
index 0b7e33d68e..58c02dce38 100644
--- a/ui/src/pages/Routines.tsx
+++ b/ui/src/pages/Routines.tsx
@@ -342,7 +342,8 @@ export function Routines() {
     resourceKey: "live-runs",
     queryKey: liveRunsQueryKey,
     enabled: !!selectedCompanyId && activeTab === "runs",
-    refetchInterval: 5000,
+    // Event-sourced via LiveUpdatesProvider (#9627); no interval poll needed.
+    refetchInterval: false,
     leaderOnly: true,
   });
   const { data: liveRuns, dataUpdatedAt: liveRunsUpdatedAt } = useQuery({
diff --git a/ui/src/plugins/bridge-init.ts b/ui/src/plugins/bridge-init.ts
index a279c5e0bd..f6370417bd 100644
--- a/ui/src/plugins/bridge-init.ts
+++ b/ui/src/plugins/bridge-init.ts
@@ -277,7 +277,8 @@ function PluginSdkIssuesList({
     resourceKey: "live-runs",
     queryKey: liveRunsQueryKey,
     enabled: !!companyId,
-    refetchInterval: 5000,
+    // Event-sourced via LiveUpdatesProvider (#9627); no interval poll needed.
+    refetchInterval: false,
     leaderOnly: true,
   });
   const { data: liveRuns, dataUpdatedAt: liveRunsUpdatedAt } = useQuery({