diff --git a/apps/web/src/components/Sidebar.browser.test.tsx b/apps/web/src/components/Sidebar.browser.test.tsx
index 64bead88b35c9..f152cabf01851 100644
--- a/apps/web/src/components/Sidebar.browser.test.tsx
+++ b/apps/web/src/components/Sidebar.browser.test.tsx
@@ -1,3 +1,7 @@
+import appCss from "../index.css?inline";
+import type { EnvironmentServerConfig } from "@t3tools/client-runtime/connection";
+import * as shelfHooks from "../state/olderSettledShelf";
+import { createWorkspaceFocusController, workspaceAreaProps } from "../lib/workspaceFocus";
 import type { EnvironmentThreadShell } from "@t3tools/client-runtime/state/shell";
 import {
   DEFAULT_CLIENT_SETTINGS,
@@ -16,7 +20,7 @@ import { makeThreadFixture } from "../test-fixtures";
 import { useHandleNewThread } from "../hooks/useHandleNewThread";
 import { __setClientSettingsForTests, getClientSettings } from "../hooks/useSettings";
 import { useThreadRouteTarget } from "../hooks/useThreadRouteTarget";
-import { useProjects, useQuietThreadShells } from "../state/entities";
+import { useProjects, useServerConfigs, useQuietThreadShells } from "../state/entities";
 import { readEnvironmentScope, useEnvironmentScope } from "../state/session";
 import { useOrchestrationCommand } from "../state/use-orchestration-command";
 import { useTerminalUiStateStore } from "../terminalUiStateStore";
@@ -26,6 +30,10 @@ import { THREAD_JUMP_HINT_SHOW_DELAY_MS } from "./Sidebar.logic";
 import { SortableThreadRow } from "./sidebar/SidebarThreadRow";
 import { SidebarProvider } from "./ui/sidebar";
 
+vi.mock(import("../state/olderSettledShelf"), async (original) => {
+  const actual = await original();
+  return { ...actual, useOlderSettledShelf: vi.fn(actual.useOlderSettledShelf) };
+});
 vi.mock("../state/entities", { spy: true });
 vi.mock("../hooks/useHandleNewThread", { spy: true });
 vi.mock("../hooks/useThreadRouteTarget", { spy: true });
@@ -135,6 +143,7 @@ describe("sidebar render isolation", () => {
       environmentId: activeProject.environmentId,
       threadId: threads[0]!.id,
     };
+    threads.unshift(threadShell(activeProject.id, 100));
     vi.mocked(useProjects).mockReturnValue([activeProject]);
     vi.mocked(useQuietThreadShells).mockReturnValue(threads);
     vi.mocked(useThreadRouteTarget).mockReturnValue({ kind: "server", threadRef: routeThreadRef });
@@ -247,3 +256,98 @@ describe("sidebar thread rename", () => {
     },
   );
 });
+
+describe("sidebar settled pagination", () => {
+  it("keeps the viewport in place when showing more settled threads", async () => {
+    using stack = new DisposableStack();
+    const style = document.createElement("style");
+    style.textContent = appCss;
+    document.head.append(style);
+    stack.defer(() => style.remove());
+    const focusController = createWorkspaceFocusController(document);
+    stack.defer(() => focusController.dispose());
+    let loading = false;
+    const originalShelf = vi.mocked(shelfHooks.useOlderSettledShelf).getMockImplementation()!;
+    using _shelf = vi.spyOn(shelfHooks, "useOlderSettledShelf").mockImplementation((input) => ({
+      ...originalShelf(input),
+      loading,
+      retry: () => {
+        loading = true;
+      },
+    }));
+    const activeProject = project("active");
+    const threads = Array.from({ length: 70 }, (_, index) =>
+      makeThreadFixture({
+        environmentId: activeProject.environmentId,
+        projectId: activeProject.id,
+        id: ThreadId.make(`settled-${index}`),
+        title: `Settled thread ${index}`,
+        settledOverride: "settled",
+        settledAt: "2026-01-01T00:00:00.000Z",
+      }),
+    );
+    threads.unshift(threadShell(activeProject.id, 100));
+    vi.mocked(useProjects).mockReturnValue([activeProject]);
+    vi.mocked(useQuietThreadShells).mockReturnValue(threads);
+    vi.mocked(useThreadRouteTarget).mockReturnValue({
+      kind: "server",
+      threadRef: { environmentId: activeProject.environmentId, threadId: threads[0]!.id },
+    });
+    vi.mocked(useHandleNewThread).mockReturnValue({
+      activeDraftThread: null,
+      activeThread: null,
+      defaultProjectRef: {
+        environmentId: activeProject.environmentId,
+        projectId: activeProject.id,
+      },
+      defaultProjectFallbackReady: true,
+      handleNewThread: vi.fn().mockResolvedValue(null),
+      routeDraftId: null,
+      routeThreadRef: { environmentId: activeProject.environmentId, threadId: threads[0]!.id },
+    });
+    vi.mocked(useServerConfigs).mockReturnValue(
+      new Map([
+        [
+          activeProject.environmentId,
+          {
+            scratchWorkspaceRoot: null,
+            shellThreadFamilies: false,
+          } as unknown as EnvironmentServerConfig,
+        ],
+      ]),
+    );
+    await using screen = await render(
+      <SidebarProvider
+        {...workspaceAreaProps("sidebar", 0, "Threads")}
+        style={{ height: 400, minHeight: 400 }}
+      >
+        <Sidebar routeReveal={{ observedKey: null, pendingKey: null }} />
+      </SidebarProvider>,
+    );
+    const shelf = screen.container.querySelector<HTMLElement>(
+      '[data-sidebar-row="shelf:settled"]',
+    )!;
+    if (shelf.getAttribute("aria-expanded") === "false") await act(() => shelf.click());
+    const more = screen.getByRole("button", { name: "Show 25 more", exact: true });
+    await expect.element(more).toBeInTheDocument();
+    const moreButton = more.element() as HTMLButtonElement;
+    const viewport = moreButton.closest<HTMLElement>('[data-slot="scroll-area-viewport"]')!;
+    viewport.style.height = "300px";
+    viewport.style.maxHeight = "300px";
+    moreButton.scrollIntoView({ block: "nearest" });
+    const before = viewport.scrollTop;
+    expect(before).toBeGreaterThan(0);
+    moreButton.focus({ preventScroll: true });
+    await act(() => moreButton.click());
+    await expect
+      .element(screen.getByRole("button", { name: "Loading", exact: true }))
+      .toBeInTheDocument();
+    await expect
+      .element(screen.getByRole("button", { name: "Loading", exact: true }))
+      .toHaveFocus();
+    expect(viewport.scrollTop).toBe(before);
+    const loadedRows = screen.container.querySelectorAll("[data-thread-item]").length;
+    await act(() => moreButton.click());
+    expect(screen.container.querySelectorAll("[data-thread-item]")).toHaveLength(loadedRows);
+  });
+});
diff --git a/apps/web/src/components/Sidebar.tsx b/apps/web/src/components/Sidebar.tsx
index 5c9203742578c..b7ec300204a05 100644
--- a/apps/web/src/components/Sidebar.tsx
+++ b/apps/web/src/components/Sidebar.tsx
@@ -3644,12 +3644,13 @@ export default function Sidebar({ routeReveal }: { routeReveal: SidebarRouteReve
                           type="button"
                           data-sidebar-row="settled:more"
                           data-sidebar-parent="shelf:settled"
-                          disabled={olderSettledShelf.loading}
+                          aria-disabled={olderSettledShelf.loading}
                           onClick={() => {
+                            if (olderSettledShelf.loading) return;
                             olderSettledShelf.retry();
                             showMoreSettled();
                           }}
-                          className="flex h-9 w-full cursor-pointer items-center gap-2.5 rounded-md px-2.5 text-left text-sm text-sidebar-muted-foreground hover:bg-sidebar-row-hover hover:text-sidebar-foreground disabled:cursor-default"
+                          className="flex h-9 w-full cursor-pointer items-center gap-2.5 rounded-md px-2.5 text-left text-sm text-sidebar-muted-foreground hover:bg-sidebar-row-hover hover:text-sidebar-foreground aria-disabled:cursor-default"
                         >
                           {/* Plus means "add", so revealing more uses a chevron. */}
                           <ChevronDownIcon aria-hidden className="size-4 shrink-0" />