diff --git a/src/cliproxy/binary-manager.ts b/src/cliproxy/binary-manager.ts
index bda4604a..f74d9257 100644
--- a/src/cliproxy/binary-manager.ts
+++ b/src/cliproxy/binary-manager.ts
@@ -9,7 +9,7 @@ import { info, warn } from '../utils/ui';
 import { getBinDir, CLIPROXY_DEFAULT_PORT } from './config-generator';
 import { BinaryInfo, BinaryManagerConfig } from './types';
 import { BACKEND_CONFIG, DEFAULT_BACKEND, CLIPROXY_MAX_STABLE_VERSION } from './platform-detector';
-import { isProxyRunning, stopProxy } from './services/proxy-lifecycle-service';
+import { stopProxy } from './services/proxy-lifecycle-service';
 import { waitForPortFree } from '../utils/port-utils';
 import { loadOrCreateUnifiedConfig } from '../config/unified-config-loader';
 import {
@@ -167,19 +167,18 @@ export async function installCliproxyVersion(
   const effectiveBackend = backend ?? getConfiguredBackend();
   const manager = new BinaryManager({ version, verbose, forceVersion: true }, effectiveBackend);
 
-  // Check if proxy is running and stop it first
-  if (isProxyRunning()) {
-    if (verbose) console.log(info('Stopping running CLIProxy before update...'));
-    const result = await stopProxy();
-    if (result.stopped) {
-      // Wait for port to be fully released
-      const portFree = await waitForPortFree(CLIPROXY_DEFAULT_PORT, 5000);
-      if (!portFree && verbose) {
-        console.log(warn('Port did not free up in time, proceeding anyway...'));
-      }
-    } else if (verbose && result.error) {
-      console.log(warn(`Could not stop proxy: ${result.error}`));
+  // Always attempt a best-effort stop first so we also catch untracked proxies
+  // that are running without a session lock.
+  if (verbose) console.log(info('Stopping running CLIProxy before update...'));
+  const result = await stopProxy();
+  if (result.stopped) {
+    // Wait for port to be fully released
+    const portFree = await waitForPortFree(CLIPROXY_DEFAULT_PORT, 5000);
+    if (!portFree && verbose) {
+      console.log(warn('Port did not free up in time, proceeding anyway...'));
     }
+  } else if (verbose && result.error && result.error !== 'No active CLIProxy session found') {
+    console.log(warn(`Could not stop proxy: ${result.error}`));
   }
 
   if (manager.isBinaryInstalled()) {
diff --git a/src/web-server/services/cliproxy-dashboard-install-service.ts b/src/web-server/services/cliproxy-dashboard-install-service.ts
index 60f99a60..7091965f 100644
--- a/src/web-server/services/cliproxy-dashboard-install-service.ts
+++ b/src/web-server/services/cliproxy-dashboard-install-service.ts
@@ -51,8 +51,8 @@ export async function installDashboardCliproxyVersion(
   const backendLabel = backend === 'plus' ? 'CLIProxy Plus' : 'CLIProxy';
   const shouldRestoreService = await wasProxyRunning(deps);
 
-  // The installer owns the stop-and-replace lifecycle: it stops a running proxy
-  // and waits for the port to free before swapping the binary.
+  // The installer owns the stop-and-replace lifecycle, including best-effort
+  // shutdown for tracked and untracked proxies before swapping the binary.
   await deps.installCliproxyVersion(version, true, backend);
 
   if (!shouldRestoreService) {
diff --git a/tests/unit/cliproxy/binary-manager-install.test.ts b/tests/unit/cliproxy/binary-manager-install.test.ts
new file mode 100644
index 00000000..b30bf963
--- /dev/null
+++ b/tests/unit/cliproxy/binary-manager-install.test.ts
@@ -0,0 +1,101 @@
+import { afterAll, beforeAll, describe, expect, it, mock } from 'bun:test';
+
+const calls = {
+  stopProxy: 0,
+  waitForPortFree: 0,
+  deleteBinary: 0,
+  ensureBinary: 0,
+};
+
+mock.module('../../../src/utils/ui', () => ({
+  info: (message: string) => message,
+  warn: (message: string) => message,
+}));
+
+mock.module('../../../src/cliproxy/config-generator', () => ({
+  getBinDir: () => '/tmp/ccs-bin',
+  CLIPROXY_DEFAULT_PORT: 8317,
+}));
+
+mock.module('../../../src/cliproxy/platform-detector', () => ({
+  DEFAULT_BACKEND: 'plus',
+  CLIPROXY_MAX_STABLE_VERSION: '6.6.80',
+  BACKEND_CONFIG: {
+    plus: {
+      fallbackVersion: '6.6.80',
+      repo: 'router-for-me/CLIProxyAPIPlus',
+    },
+    original: {
+      fallbackVersion: '0.0.0',
+      repo: 'router-for-me/CLIProxyAPI',
+    },
+  },
+}));
+
+mock.module('../../../src/cliproxy/services/proxy-lifecycle-service', () => ({
+  stopProxy: async () => {
+    calls.stopProxy += 1;
+    return { stopped: false, error: 'No active CLIProxy session found' };
+  },
+}));
+
+mock.module('../../../src/utils/port-utils', () => ({
+  waitForPortFree: async () => {
+    calls.waitForPortFree += 1;
+    return true;
+  },
+}));
+
+mock.module('../../../src/config/unified-config-loader', () => ({
+  loadOrCreateUnifiedConfig: () => ({
+    cliproxy: { backend: 'plus' },
+  }),
+}));
+
+mock.module('../../../src/cliproxy/binary', () => ({
+  checkForUpdates: async () => ({
+    hasUpdate: false,
+    currentVersion: '6.6.80',
+    latestVersion: '6.6.80',
+    fromCache: false,
+    checkedAt: Date.now(),
+  }),
+  deleteBinary: () => {
+    calls.deleteBinary += 1;
+  },
+  getBinaryPath: () => '/tmp/ccs-bin/plus/cliproxy',
+  isBinaryInstalled: () => false,
+  getBinaryInfo: async () => null,
+  getPinnedVersion: () => null,
+  savePinnedVersion: () => {},
+  clearPinnedVersion: () => {},
+  isVersionPinned: () => false,
+  getVersionPinPath: () => '/tmp/ccs-bin/plus/.version-pin',
+  readInstalledVersion: () => '6.6.80',
+  ensureBinary: async () => {
+    calls.ensureBinary += 1;
+    return '/tmp/ccs-bin/plus/cliproxy';
+  },
+  migrateVersionPin: () => {},
+}));
+
+let binaryManager: typeof import('../../../src/cliproxy/binary-manager');
+
+beforeAll(async () => {
+  binaryManager = await import('../../../src/cliproxy/binary-manager');
+});
+
+afterAll(() => {
+  mock.restore();
+});
+
+describe('installCliproxyVersion', () => {
+  it('attempts to stop the proxy even when there is no tracked running session', async () => {
+    await binaryManager.installCliproxyVersion('6.7.1', false, 'plus');
+
+    expect(calls.stopProxy).toBe(1);
+    expect(calls.waitForPortFree).toBe(0);
+    expect(calls.deleteBinary).toBe(0);
+    expect(calls.ensureBinary).toBe(1);
+  });
+});