diff --git a/client/src/pages/LiveCamera.tsx b/client/src/pages/LiveCamera.tsx
index 85fbe93..0eb248c 100644
--- a/client/src/pages/LiveCamera.tsx
+++ b/client/src/pages/LiveCamera.tsx
@@ -219,6 +219,35 @@ function formatDuration(ms: number) {
   return `${minutes.toString().padStart(2, "0")}:${seconds.toString().padStart(2, "0")}`;
 }
 
+function normalizeRuntimeTitle(value: string | null | undefined) {
+  if (typeof value !== "string") return "";
+  const trimmed = value.trim();
+  if (!trimmed) return "";
+
+  const suspicious = /[ÃÂÆÐÑØæåçéèêëïîôöûüœŠŽƒ€¦]/;
+  if (!suspicious.test(trimmed)) {
+    return trimmed;
+  }
+
+  try {
+    const bytes = Uint8Array.from(Array.from(trimmed).map((char) => char.charCodeAt(0) & 0xff));
+    const decoded = new TextDecoder("utf-8").decode(bytes).trim();
+    if (!decoded || decoded === trimmed) {
+      return trimmed;
+    }
+
+    const score = (text: string) => {
+      const cjkCount = text.match(/[\u3400-\u9fff]/g)?.length ?? 0;
+      const badCount = text.match(/[ÃÂÆÐÑØæåçéèêëïîôöûüœŠŽƒ€¦]/g)?.length ?? 0;
+      return (cjkCount * 2) - badCount;
+    };
+
+    return score(decoded) > score(trimmed) ? decoded : trimmed;
+  } catch {
+    return trimmed;
+  }
+}
+
 function isMobileDevice() {
   if (typeof window === "undefined") return false;
   return /Android|iPhone|iPad|iPod/i.test(navigator.userAgent) || window.matchMedia("(max-width: 768px)").matches;
@@ -648,6 +677,8 @@ export default function LiveCamera() {
   const runtimeRole = (runtimeQuery.data?.role ?? "idle") as RuntimeRole;
   const runtimeSession = (runtimeQuery.data?.runtimeSession ?? null) as RuntimeSession | null;
   const runtimeSnapshot = runtimeSession?.snapshot ?? null;
+  const normalizedRuntimeTitle = normalizeRuntimeTitle(runtimeSession?.title);
+  const normalizedSnapshotTitle = normalizeRuntimeTitle(runtimeSnapshot?.title);
 
   useEffect(() => {
     avatarRenderRef.current = {
@@ -763,6 +794,14 @@ export default function LiveCamera() {
     [displayVisibleSegments.length, knownRatio, liveScore?.overall, runtimeRole, runtimeSnapshot?.liveScore?.overall],
   );
 
+  const refreshRuntimeState = useCallback(async () => {
+    const result = await runtimeQuery.refetch();
+    return {
+      role: (result.data?.role ?? runtimeRole) as RuntimeRole,
+      runtimeSession: (result.data?.runtimeSession ?? runtimeSession) as RuntimeSession | null,
+    };
+  }, [runtimeQuery, runtimeRole, runtimeSession]);
+
   useEffect(() => {
     navigator.mediaDevices?.enumerateDevices().then((devices) => {
       const cameras = devices.filter((device) => device.kind === "videoinput");
@@ -872,7 +911,7 @@ export default function LiveCamera() {
     phase: phase ?? leaveStatusRef.current,
     startedAt: sessionStartedAtRef.current || undefined,
     durationMs: durationMsRef.current,
-    title: runtimeSession?.title ?? `实时分析 ${ACTION_META[currentActionRef.current].label}`,
+    title: normalizedRuntimeTitle || `实时分析 ${ACTION_META[currentActionRef.current].label}`,
     sessionMode: sessionModeRef.current,
     qualityPreset,
     facingMode: facing,
@@ -890,7 +929,17 @@ export default function LiveCamera() {
     unknownSegments: segmentsRef.current.filter((segment) => segment.isUnknown).length,
     archivedVideoCount: archivedVideosRef.current.length,
     recentSegments: segmentsRef.current.slice(-5),
-  }), [facing, mobile, qualityPreset, runtimeSession?.title]);
+  }), [facing, mobile, normalizedRuntimeTitle, qualityPreset]);
+
+  const openSetupGuide = useCallback(async () => {
+    const latest = await refreshRuntimeState();
+    if (latest.role === "viewer") {
+      setShowSetupGuide(false);
+      toast.error("当前账号已有其他设备正在实时分析，请先切换到同步观看模式");
+      return;
+    }
+    setShowSetupGuide(true);
+  }, [refreshRuntimeState]);
 
   const uploadLiveFrame = useCallback(async (sessionId: string) => {
     const compositeCanvas = ensureCompositeCanvas();
@@ -1162,7 +1211,8 @@ export default function LiveCamera() {
     preferredZoom = zoomTargetRef.current,
     preset: CameraQualityPreset = qualityPreset,
   ) => {
-    if (runtimeRole === "viewer") {
+    const latest = await refreshRuntimeState();
+    if (latest.role === "viewer") {
       toast.error("当前账号已有其他设备正在实时分析，请切换到同步观看模式");
       return;
     }
@@ -1179,12 +1229,16 @@ export default function LiveCamera() {
       if (appliedFacingMode !== nextFacing) {
         setFacing(appliedFacingMode);
       }
+      setCameraActive(true);
       if (videoRef.current) {
-        videoRef.current.srcObject = stream;
-        await videoRef.current.play();
+        try {
+          videoRef.current.srcObject = stream;
+          await videoRef.current.play().catch(() => undefined);
+        } catch {
+          // Keep the camera session alive even if preview binding is flaky on the current browser.
+        }
       }
       await syncZoomState(preferredZoom, stream.getVideoTracks()[0] || null);
-      setCameraActive(true);
       if (usedFallback) {
         toast.info("当前设备已自动切换到兼容摄像头模式");
       }
@@ -1192,7 +1246,7 @@ export default function LiveCamera() {
     } catch (error: any) {
       toast.error(`摄像头启动失败: ${error?.message || "未知错误"}`);
     }
-  }, [facing, mobile, qualityPreset, runtimeRole, syncZoomState]);
+  }, [facing, mobile, qualityPreset, refreshRuntimeState, syncZoomState]);
 
   const switchCamera = useCallback(async () => {
     const nextFacing: CameraFacing = facing === "user" ? "environment" : "user";
@@ -1417,12 +1471,13 @@ export default function LiveCamera() {
   }, [flushSegment, liveScore, mobile, saveLiveSessionMutation, sessionMode, stopSessionRecorder]);
 
   const startAnalysis = useCallback(async () => {
+    const latest = await refreshRuntimeState();
     if (!cameraActive || !videoRef.current || !streamRef.current) {
       toast.error("请先启动摄像头");
       return;
     }
     if (analyzingRef.current || saving) return;
-    if (runtimeRole === "viewer") {
+    if (latest.role === "viewer") {
       toast.error("当前设备处于同步观看模式，不能重复开启分析");
       return;
     }
@@ -1570,10 +1625,10 @@ export default function LiveCamera() {
     appendFrameToSegment,
     cameraActive,
     closeBroadcastPeer,
+    refreshRuntimeState,
     releaseRuntime,
     runtimeAcquireMutation,
     runtimeQuery,
-    runtimeRole,
     saving,
     sessionMode,
     startBroadcastSession,
@@ -1632,9 +1687,15 @@ export default function LiveCamera() {
   }, [analyzing, saving]);
 
   const handleSetupComplete = useCallback(async () => {
+    const latest = await refreshRuntimeState();
+    if (latest.role === "viewer") {
+      setShowSetupGuide(false);
+      toast.error("当前账号已有其他设备正在实时分析，请切换到同步观看模式");
+      return;
+    }
     setShowSetupGuide(false);
     await startCamera(facing, zoomTargetRef.current, qualityPreset);
-  }, [facing, qualityPreset, startCamera]);
+  }, [facing, qualityPreset, refreshRuntimeState, startCamera]);
 
   const displayLeaveStatus = runtimeRole === "viewer" ? (runtimeSnapshot?.phase ?? "idle") : leaveStatus;
   const displayAction = runtimeRole === "viewer" ? (runtimeSnapshot?.currentAction ?? "unknown") : currentAction;
@@ -1673,8 +1734,8 @@ export default function LiveCamera() {
   const runtimeSyncDelayMs = runtimeRole === "viewer" ? getRuntimeSyncDelayMs(runtimeSession?.lastHeartbeatAt) : null;
   const runtimeSyncLabel = runtimeRole === "viewer" ? formatRuntimeSyncDelay(runtimeSyncDelayMs) : "";
   const displayRuntimeTitle = runtimeRole === "viewer"
-    ? (runtimeSnapshot?.title ?? runtimeSession?.title ?? "其他设备实时分析")
-    : (runtimeSession?.title ?? `实时分析 ${ACTION_META[currentAction].label}`);
+    ? (normalizedSnapshotTitle || normalizedRuntimeTitle || "其他设备实时分析")
+    : (normalizedRuntimeTitle || `实时分析 ${ACTION_META[currentAction].label}`);
   const viewerFrameSrc = runtimeRole === "viewer" && runtimeSession?.mediaSessionId
     ? getMediaAssetUrl(`/assets/sessions/${runtimeSession.mediaSessionId}/live-frame.jpg?ts=${viewerFrameVersion || runtimeSnapshot?.updatedAt || Date.now()}`)
     : "";
@@ -1698,7 +1759,7 @@ export default function LiveCamera() {
         ? "准备开始实时分析"
         : "摄像头待启动";
 
-  const viewerModeLabel = runtimeSession?.title || "其他设备正在实时分析";
+  const viewerModeLabel = normalizedRuntimeTitle || "其他设备正在实时分析";
 
   const renderPrimaryActions = (rail = false) => {
     const buttonClass = rail
@@ -1738,7 +1799,7 @@ export default function LiveCamera() {
         <Button
           data-testid={rail ? undefined : "live-camera-toolbar-start-button"}
           className={buttonClass}
-          onClick={() => setShowSetupGuide(true)}
+          onClick={() => void openSetupGuide()}
         >
           <Camera className={rail ? "h-5 w-5" : "mr-2 h-4 w-4"} />
           {!rail && "启动摄像头"}
@@ -2120,7 +2181,7 @@ export default function LiveCamera() {
                         {viewerConnected ? "刷新同步" : "获取同步画面"}
                       </Button>
                     ) : (
-                      <Button data-testid="live-camera-start-button" onClick={() => setShowSetupGuide(true)} className="rounded-2xl">
+                      <Button data-testid="live-camera-start-button" onClick={() => void openSetupGuide()} className="rounded-2xl">
                         <Camera className="mr-2 h-4 w-4" />
                         启动摄像头
                       </Button>
diff --git a/tests/e2e/app.spec.ts b/tests/e2e/app.spec.ts
index 34d74d2..63496ff 100644
--- a/tests/e2e/app.spec.ts
+++ b/tests/e2e/app.spec.ts
@@ -82,7 +82,23 @@ test("live camera switches into viewer mode when another device already owns ana
   await expect(page.getByTestId("live-camera-score-overall")).toBeVisible();
 });
 
-test("live camera retries viewer stream when owner track is not ready on first attempt", async ({ page }) => {
+test("live camera recovers mojibake viewer titles before rendering", async ({ page }) => {
+  const state = await installAppMocks(page, { authenticated: true, liveViewerMode: true });
+  const mojibakeTitle = Buffer.from("服务端同步烟雾测试", "utf8").toString("latin1");
+  if (state.liveRuntime.runtimeSession) {
+    state.liveRuntime.runtimeSession.title = mojibakeTitle;
+    state.liveRuntime.runtimeSession.snapshot = {
+      ...state.liveRuntime.runtimeSession.snapshot,
+      title: mojibakeTitle,
+    };
+  }
+
+  await page.goto("/live-camera");
+  await expect(page.getByRole("heading", { name: "服务端同步烟雾测试" })).toBeVisible();
+  await expect(page.getByText(mojibakeTitle)).toHaveCount(0);
+});
+
+test("live camera no longer opens viewer peer retries when server relay is active", async ({ page }) => {
   const state = await installAppMocks(page, {
     authenticated: true,
     liveViewerMode: true,
@@ -91,9 +107,9 @@ test("live camera retries viewer stream when owner track is not ready on first a
 
   await page.goto("/live-camera");
   await expect(page.getByText("同步观看模式")).toBeVisible();
-  await expect.poll(() => state.viewerSignalConflictRemaining).toBe(0);
-  await expect.poll(() => state.mediaSession?.viewerCount ?? 0).toBe(1);
-  await expect(page.getByText(/同步观看中|重新同步/).first()).toBeVisible();
+  await expect.poll(() => state.viewerSignalConflictRemaining).toBe(1);
+  await expect.poll(() => state.mediaSession?.viewerCount ?? 0).toBe(0);
+  await expect(page.locator('img[alt="同步中的实时分析画面"]')).toBeVisible();
 });
 
 test("live camera archives overlay videos into the library after analysis stops", async ({ page }) => {
diff --git a/tests/e2e/helpers/mockApp.ts b/tests/e2e/helpers/mockApp.ts
index c8e2380..db5bb25 100644
--- a/tests/e2e/helpers/mockApp.ts
+++ b/tests/e2e/helpers/mockApp.ts
@@ -866,6 +866,73 @@ export async function installAppMocks(
       return points;
     };
 
+    class FakeVideoTrack {
+      kind = "video";
+      enabled = true;
+      muted = false;
+      readyState = "live";
+      id = "fake-video-track";
+      label = "Fake Camera";
+
+      stop() {}
+
+      getSettings() {
+        return {
+          facingMode: "environment",
+          width: 1280,
+          height: 720,
+          frameRate: 30,
+        };
+      }
+
+      getCapabilities() {
+        return {};
+      }
+
+      async applyConstraints() {
+        return undefined;
+      }
+    }
+
+    class FakeAudioTrack {
+      kind = "audio";
+      enabled = true;
+      muted = false;
+      readyState = "live";
+      id = "fake-audio-track";
+      label = "Fake Mic";
+
+      stop() {}
+
+      getSettings() {
+        return {};
+      }
+
+      getCapabilities() {
+        return {};
+      }
+
+      async applyConstraints() {
+        return undefined;
+      }
+    }
+
+    const createFakeMediaStream = (withAudio = false) => {
+      const videoTrack = new FakeVideoTrack();
+      const audioTrack = withAudio ? new FakeAudioTrack() : null;
+      const tracks = audioTrack ? [videoTrack, audioTrack] : [videoTrack];
+      return {
+        active: true,
+        id: `fake-stream-${Math.random().toString(36).slice(2)}`,
+        getTracks: () => tracks,
+        getVideoTracks: () => [videoTrack],
+        getAudioTracks: () => (audioTrack ? [audioTrack] : []),
+        addTrack: () => undefined,
+        removeTrack: () => undefined,
+        clone: () => createFakeMediaStream(withAudio),
+      } as unknown as MediaStream;
+    };
+
     class FakePose {
       callback = null;
 
@@ -894,9 +961,19 @@ export async function installAppMocks(
       value: async () => undefined,
     });
 
+    Object.defineProperty(HTMLMediaElement.prototype, "srcObject", {
+      configurable: true,
+      get() {
+        return (this as HTMLMediaElement & { __srcObject?: MediaStream }).__srcObject ?? null;
+      },
+      set(value) {
+        (this as HTMLMediaElement & { __srcObject?: MediaStream }).__srcObject = value as MediaStream;
+      },
+    });
+
     Object.defineProperty(HTMLCanvasElement.prototype, "captureStream", {
       configurable: true,
-      value: () => new MediaStream(),
+      value: () => createFakeMediaStream(),
     });
 
     class FakeMediaRecorder extends EventTarget {
@@ -961,7 +1038,7 @@ export async function installAppMocks(
       async setRemoteDescription(description: { type: string; sdp: string }) {
         this.remoteDescription = description;
         this.connectionState = "connected";
-        this.ontrack?.({ streams: [new MediaStream()] });
+        this.ontrack?.({ streams: [createFakeMediaStream()] });
         this.onconnectionstatechange?.();
       }
 
@@ -984,7 +1061,7 @@ export async function installAppMocks(
     Object.defineProperty(navigator, "mediaDevices", {
       configurable: true,
       value: {
-        getUserMedia: async () => new MediaStream(),
+        getUserMedia: async (constraints?: { audio?: unknown }) => createFakeMediaStream(Boolean(constraints?.audio)),
         enumerateDevices: async () => [
           { deviceId: "cam-1", kind: "videoinput", label: "Front Camera", groupId: "g1" },
           { deviceId: "cam-2", kind: "videoinput", label: "Back Camera", groupId: "g1" },