diff --git a/CHANGELOG.md b/CHANGELOG.md
index 95d6041400..ba0f382bb7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -18,6 +18,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Voice call/Gateway: prevent overlapping closed-loop turn races with per-call turn locking, route transcript dedupe via source-aware fingerprints with strict cache eviction bounds, and harden `voicecall latency` stats for large logs without spread-operator stack overflow. (#19140) Thanks @mbelinky.
 - Fix types in all tests. Typecheck the whole repository.
 - Voice-call: auto-end calls when media streams disconnect to prevent stuck active calls. (#18435) Thanks @JayMishra-source.
 - Gateway/Channels: wire `gateway.channelHealthCheckMinutes` into strict config validation, treat implicit account status as managed for health checks, and harden channel auto-restart flow (preserve restart-attempt caps across crash loops, propagate enabled/configured runtime flags, and stop pending restart backoff after manual stop). Thanks @steipete.
diff --git a/extensions/voice-call/src/cli.ts b/extensions/voice-call/src/cli.ts
index 5127a9791a..963fa6f517 100644
--- a/extensions/voice-call/src/cli.ts
+++ b/extensions/voice-call/src/cli.ts
@@ -62,8 +62,8 @@ function summarizeSeries(values: number[]): {
     return { count: 0, minMs: 0, maxMs: 0, avgMs: 0, p50Ms: 0, p95Ms: 0 };
   }
 
-  const minMs = Math.min(...values);
-  const maxMs = Math.max(...values);
+  const minMs = values.reduce((min, value) => (value < min ? value : min), Number.POSITIVE_INFINITY);
+  const maxMs = values.reduce((max, value) => (value > max ? value : max), Number.NEGATIVE_INFINITY);
   const avgMs = values.reduce((sum, value) => sum + value, 0) / values.length;
   return {
     count: values.length,
diff --git a/extensions/voice-call/src/manager.test.ts b/extensions/voice-call/src/manager.test.ts
index aa8b2f76f2..3d02cb323b 100644
--- a/extensions/voice-call/src/manager.test.ts
+++ b/extensions/voice-call/src/manager.test.ts
@@ -347,8 +347,6 @@ describe("CallManager", () => {
     });
 
     const first = manager.continueCall(started.callId, "First prompt");
-    await new Promise((resolve) => setTimeout(resolve, 0));
-
     const second = await manager.continueCall(started.callId, "Second prompt");
     expect(second.success).toBe(false);
     expect(second.error).toBe("Already waiting for transcript");
diff --git a/extensions/voice-call/src/manager.ts b/extensions/voice-call/src/manager.ts
index d2c7d6eae8..927899f325 100644
--- a/extensions/voice-call/src/manager.ts
+++ b/extensions/voice-call/src/manager.ts
@@ -47,6 +47,7 @@ export class CallManager {
   private config: VoiceCallConfig;
   private storePath: string;
   private webhookUrl: string | null = null;
+  private activeTurnCalls = new Set<CallId>();
   private transcriptWaiters = new Map<
     CallId,
     {
@@ -137,6 +138,7 @@ export class CallManager {
       config: this.config,
       storePath: this.storePath,
       webhookUrl: this.webhookUrl,
+      activeTurnCalls: this.activeTurnCalls,
       transcriptWaiters: this.transcriptWaiters,
       maxDurationTimers: this.maxDurationTimers,
       onCallAnswered: (call) => {
diff --git a/extensions/voice-call/src/manager/context.ts b/extensions/voice-call/src/manager/context.ts
index 03cbd3c1e1..1af703ed32 100644
--- a/extensions/voice-call/src/manager/context.ts
+++ b/extensions/voice-call/src/manager/context.ts
@@ -24,6 +24,7 @@ export type CallManagerRuntimeDeps = {
 };
 
 export type CallManagerTransientState = {
+  activeTurnCalls: Set<CallId>;
   transcriptWaiters: Map<CallId, TranscriptWaiter>;
   maxDurationTimers: Map<CallId, NodeJS.Timeout>;
 };
diff --git a/extensions/voice-call/src/manager/events.test.ts b/extensions/voice-call/src/manager/events.test.ts
index 8407c9cc65..74d1f10e46 100644
--- a/extensions/voice-call/src/manager/events.test.ts
+++ b/extensions/voice-call/src/manager/events.test.ts
@@ -24,6 +24,7 @@ function createContext(overrides: Partial<CallManagerContext> = {}): CallManager
     }),
     storePath,
     webhookUrl: null,
+    activeTurnCalls: new Set(),
     transcriptWaiters: new Map(),
     maxDurationTimers: new Map(),
     ...overrides,
diff --git a/extensions/voice-call/src/manager/outbound.ts b/extensions/voice-call/src/manager/outbound.ts
index 61fe4567fd..d94c9da99e 100644
--- a/extensions/voice-call/src/manager/outbound.ts
+++ b/extensions/voice-call/src/manager/outbound.ts
@@ -36,6 +36,7 @@ type ConversationContext = Pick<
   | "provider"
   | "config"
   | "storePath"
+  | "activeTurnCalls"
   | "transcriptWaiters"
   | "maxDurationTimers"
 >;
@@ -241,9 +242,10 @@ export async function continueCall(
   if (TerminalStates.has(call.state)) {
     return { success: false, error: "Call has ended" };
   }
-  if (ctx.transcriptWaiters.has(callId)) {
+  if (ctx.activeTurnCalls.has(callId) || ctx.transcriptWaiters.has(callId)) {
     return { success: false, error: "Already waiting for transcript" };
   }
+  ctx.activeTurnCalls.add(callId);
 
   const turnStartedAt = Date.now();
 
@@ -291,6 +293,7 @@ export async function continueCall(
   } catch (err) {
     return { success: false, error: err instanceof Error ? err.message : String(err) };
   } finally {
+    ctx.activeTurnCalls.delete(callId);
     clearTranscriptWaiter(ctx, callId);
   }
 }
diff --git a/extensions/voice-call/src/manager/timers.ts b/extensions/voice-call/src/manager/timers.ts
index 116920e993..236ffa1435 100644
--- a/extensions/voice-call/src/manager/timers.ts
+++ b/extensions/voice-call/src/manager/timers.ts
@@ -87,8 +87,9 @@ export function resolveTranscriptWaiter(
 }
 
 export function waitForFinalTranscript(ctx: TimerContext, callId: CallId): Promise<string> {
-  // Only allow one in-flight waiter per call.
-  rejectTranscriptWaiter(ctx, callId, "Transcript waiter replaced");
+  if (ctx.transcriptWaiters.has(callId)) {
+    return Promise.reject(new Error("Already waiting for transcript"));
+  }
 
   const timeoutMs = ctx.config.transcriptTimeoutMs;
   return new Promise((resolve, reject) => {
diff --git a/src/gateway/server-node-events.test.ts b/src/gateway/server-node-events.test.ts
index 0b0788e0b8..77530882e3 100644
--- a/src/gateway/server-node-events.test.ts
+++ b/src/gateway/server-node-events.test.ts
@@ -198,6 +198,30 @@ describe("voice transcript events", () => {
     expect(updateSessionStoreMock).toHaveBeenCalledTimes(1);
   });
 
+  it("does not dedupe identical text when source event IDs differ", async () => {
+    const ctx = buildCtx();
+
+    await handleNodeEvent(ctx, "node-v1", {
+      event: "voice.transcript",
+      payloadJSON: JSON.stringify({
+        text: "hello from mic",
+        sessionKey: "voice-dedupe-eventid-session",
+        eventId: "evt-voice-1",
+      }),
+    });
+    await handleNodeEvent(ctx, "node-v1", {
+      event: "voice.transcript",
+      payloadJSON: JSON.stringify({
+        text: "hello from mic",
+        sessionKey: "voice-dedupe-eventid-session",
+        eventId: "evt-voice-2",
+      }),
+    });
+
+    expect(agentCommandMock).toHaveBeenCalledTimes(2);
+    expect(updateSessionStoreMock).toHaveBeenCalledTimes(2);
+  });
+
   it("forwards transcript with voice provenance", async () => {
     const ctx = buildCtx();
 
diff --git a/src/gateway/server-node-events.ts b/src/gateway/server-node-events.ts
index 93f1255bb5..bd662a126a 100644
--- a/src/gateway/server-node-events.ts
+++ b/src/gateway/server-node-events.ts
@@ -19,22 +19,64 @@ const MAX_EXEC_EVENT_OUTPUT_CHARS = 180;
 const VOICE_TRANSCRIPT_DEDUPE_WINDOW_MS = 1500;
 const MAX_RECENT_VOICE_TRANSCRIPTS = 200;
 
-const recentVoiceTranscripts = new Map<string, { text: string; ts: number }>();
+const recentVoiceTranscripts = new Map<string, { fingerprint: string; ts: number }>();
+
+function normalizeNonEmptyString(value: unknown): string | null {
+  if (typeof value !== "string") {
+    return null;
+  }
+  const trimmed = value.trim();
+  return trimmed.length > 0 ? trimmed : null;
+}
+
+function normalizeFiniteInteger(value: unknown): number | null {
+  return typeof value === "number" && Number.isFinite(value) ? Math.trunc(value) : null;
+}
+
+function resolveVoiceTranscriptFingerprint(obj: Record<string, unknown>, text: string): string {
+  const eventId =
+    normalizeNonEmptyString(obj.eventId) ??
+    normalizeNonEmptyString(obj.providerEventId) ??
+    normalizeNonEmptyString(obj.transcriptId);
+  if (eventId) {
+    return `event:${eventId}`;
+  }
+
+  const callId = normalizeNonEmptyString(obj.providerCallId) ?? normalizeNonEmptyString(obj.callId);
+  const sequence = normalizeFiniteInteger(obj.sequence) ?? normalizeFiniteInteger(obj.seq);
+  if (callId && sequence !== null) {
+    return `call-seq:${callId}:${sequence}`;
+  }
+
+  const eventTimestamp =
+    normalizeFiniteInteger(obj.timestamp) ??
+    normalizeFiniteInteger(obj.ts) ??
+    normalizeFiniteInteger(obj.eventTimestamp);
+  if (callId && eventTimestamp !== null) {
+    return `call-ts:${callId}:${eventTimestamp}`;
+  }
+
+  if (eventTimestamp !== null) {
+    return `timestamp:${eventTimestamp}|text:${text}`;
+  }
+
+  return `text:${text}`;
+}
 
 function shouldDropDuplicateVoiceTranscript(params: {
   sessionKey: string;
-  text: string;
+  fingerprint: string;
   now: number;
 }): boolean {
   const previous = recentVoiceTranscripts.get(params.sessionKey);
   if (
     previous &&
-    previous.text === params.text &&
+    previous.fingerprint === params.fingerprint &&
     params.now - previous.ts <= VOICE_TRANSCRIPT_DEDUPE_WINDOW_MS
   ) {
     return true;
   }
-  recentVoiceTranscripts.set(params.sessionKey, { text: params.text, ts: params.now });
+  recentVoiceTranscripts.set(params.sessionKey, { fingerprint: params.fingerprint, ts: params.now });
 
   if (recentVoiceTranscripts.size > MAX_RECENT_VOICE_TRANSCRIPTS) {
     const cutoff = params.now - VOICE_TRANSCRIPT_DEDUPE_WINDOW_MS * 2;
@@ -46,6 +88,13 @@ function shouldDropDuplicateVoiceTranscript(params: {
         break;
       }
     }
+    while (recentVoiceTranscripts.size > MAX_RECENT_VOICE_TRANSCRIPTS) {
+      const oldestKey = recentVoiceTranscripts.keys().next().value;
+      if (oldestKey === undefined) {
+        break;
+      }
+      recentVoiceTranscripts.delete(oldestKey);
+    }
   }
 
   return false;
@@ -168,7 +217,8 @@ export const handleNodeEvent = async (ctx: NodeEventContext, nodeId: string, evt
       const sessionKey = sessionKeyRaw.length > 0 ? sessionKeyRaw : rawMainKey;
       const { storePath, entry, canonicalKey } = loadSessionEntry(sessionKey);
       const now = Date.now();
-      if (shouldDropDuplicateVoiceTranscript({ sessionKey: canonicalKey, text, now })) {
+      const fingerprint = resolveVoiceTranscriptFingerprint(obj, text);
+      if (shouldDropDuplicateVoiceTranscript({ sessionKey: canonicalKey, fingerprint, now })) {
         return;
       }
       const sessionId = entry?.sessionId ?? randomUUID();