diff --git a/extensions/signal/src/setup-managed-validation-integration.test.ts b/extensions/signal/src/setup-managed-validation-integration.test.ts
index 899ae4998c8f..3f0ddf838c18 100644
--- a/extensions/signal/src/setup-managed-validation-integration.test.ts
+++ b/extensions/signal/src/setup-managed-validation-integration.test.ts
@@ -110,7 +110,7 @@ describe("Signal managed setup validation wiring", () => {
     );
   });
 
-  it("keeps the original account identity when the generic input changes A to B", async () => {
+  it("validates an account replacement on a distinct persisted port", async () => {
     const originalCfg: OpenClawConfig = {
       channels: {
         signal: {
@@ -129,7 +129,7 @@ describe("Signal managed setup validation wiring", () => {
       },
     };
 
-    await runSetupWizardFinalize({
+    const finalized = await runSetupWizardFinalize({
       finalize: signalSetupWizard.finalize,
       cfg: changedCfg,
       credentialValues,
@@ -142,8 +142,12 @@ describe("Signal managed setup validation wiring", () => {
         account: "+15555550124",
         reusableConfiguredAccount: "+15555550123",
         reusableConfiguredTransport: expect.any(String),
+        transport: expect.objectContaining({ httpPort: 8081 }),
       }),
     );
+    expect(finalized?.cfg?.channels?.signal?.transport).toEqual(
+      expect.objectContaining({ httpPort: 8081 }),
+    );
   });
 
   it("propagates setup cancellation without entering readiness recovery", async () => {
diff --git a/extensions/signal/src/setup-managed-validation.test.ts b/extensions/signal/src/setup-managed-validation.test.ts
index 43bac94e921a..32a8fffef871 100644
--- a/extensions/signal/src/setup-managed-validation.test.ts
+++ b/extensions/signal/src/setup-managed-validation.test.ts
@@ -208,26 +208,28 @@ describe("probeManagedSignalSetup", () => {
     expect(mocks.spawnDaemon).not.toHaveBeenCalled();
   });
 
-  it("never reuses the old daemon after the selected account changes", async () => {
+  it("validates a replacement account on its newly allocated port", async () => {
     const changedAccount = "+15555550124";
+    const replacementTransport = { ...transport, httpPort: 8081 };
     const cfg = {
       channels: {
         signal: { accounts: { work: { account: changedAccount, transport } } },
       },
     } as OpenClawConfig;
-    mocks.assertBindAvailable.mockRejectedValueOnce(new Error("address in use (EADDRINUSE)"));
 
     await expect(
       probeManagedSignalSetup({
-        ...createParams(cfg, transport, account),
+        ...createParams(cfg, replacementTransport, account),
         account: changedAccount,
       }),
-    ).resolves.toMatchObject({
-      ok: false,
-      error: expect.stringContaining("EADDRINUSE"),
+    ).resolves.toMatchObject({ ok: true });
+    expect(mocks.assertBindAvailable).toHaveBeenCalledWith({
+      httpHost: "127.0.0.1",
+      httpPort: 8081,
     });
-    expect(mocks.probeTransport).not.toHaveBeenCalled();
-    expect(mocks.spawnDaemon).not.toHaveBeenCalled();
+    expect(mocks.spawnDaemon).toHaveBeenCalledWith(
+      expect.objectContaining({ account: changedAccount, httpPort: 8081 }),
+    );
   });
 
   it("spawns the selected account on the final port and always stops it", async () => {
diff --git a/extensions/signal/src/setup-surface.ts b/extensions/signal/src/setup-surface.ts
index e9f136bb22fd..3d998c091340 100644
--- a/extensions/signal/src/setup-surface.ts
+++ b/extensions/signal/src/setup-surface.ts
@@ -312,9 +312,17 @@ export const signalSetupWizard: ChannelSetupWizard = {
     if (!account) {
       throw new Error("Signal managed setup requires an account number before validation.");
     }
+    const reusableConfiguredAccount = normalizeSignalAccountInput(
+      params.credentialValues[signalSetupStateKeys.managedReuseAccount],
+    );
     const transport = prepareSignalManagedNativeTransport({
       cfg: params.cfg,
       accountId: params.accountId,
+      // The old account keeps its daemon port until whole-channel reload drains it. Treat an
+      // identity replacement as a new bind so setup validates the exact transport it persists.
+      reserveTargetAccountPorts: Boolean(
+        reusableConfiguredAccount && reusableConfiguredAccount !== account,
+      ),
       overrides:
         typeof params.credentialValues.cliPath === "string"
           ? { cliPath: params.credentialValues.cliPath }
@@ -326,8 +334,7 @@ export const signalSetupWizard: ChannelSetupWizard = {
         accountId: params.accountId,
         transport,
         account,
-        reusableConfiguredAccount:
-          params.credentialValues[signalSetupStateKeys.managedReuseAccount],
+        reusableConfiguredAccount,
         reusableConfiguredTransport:
           params.credentialValues[signalSetupStateKeys.managedReuseTransport],
         runtime: params.runtime,
diff --git a/extensions/signal/src/setup-transport.test.ts b/extensions/signal/src/setup-transport.test.ts
index ba5e2e249a1d..81d612aee366 100644
--- a/extensions/signal/src/setup-transport.test.ts
+++ b/extensions/signal/src/setup-transport.test.ts
@@ -267,6 +267,42 @@ describe("prepareSignalManagedNativeTransport", () => {
     });
   });
 
+  it("reserves an inherited target port while replacing its account identity", () => {
+    const cfg = {
+      channels: {
+        signal: {
+          accounts: {
+            work: {
+              account: "+15555550124",
+              transport: {
+                kind: "managed-native",
+                url: "http://127.0.0.1:8080",
+                httpPort: 8080,
+              },
+            },
+            personal: {
+              account: "+15555550123",
+              transport: { kind: "managed-native", httpPort: 8081 },
+            },
+          },
+        },
+      },
+    } as const;
+
+    expect(
+      prepareSignalManagedNativeTransport({
+        cfg: cfg as never,
+        accountId: "work",
+        reserveTargetAccountPorts: true,
+      }),
+    ).toEqual({
+      kind: "managed-native",
+      url: "http://127.0.0.1:8082",
+      httpHost: "127.0.0.1",
+      httpPort: 8082,
+    });
+  });
+
   it("keeps an aligned managed connection URL on the allocated bind port", () => {
     const cfg = {
       channels: {
diff --git a/extensions/signal/src/setup-transport.ts b/extensions/signal/src/setup-transport.ts
index 63c2735fb1f4..4f361519d9c3 100644
--- a/extensions/signal/src/setup-transport.ts
+++ b/extensions/signal/src/setup-transport.ts
@@ -156,6 +156,7 @@ export function prepareSignalManagedNativeTransport(params: {
   cfg: OpenClawConfig;
   accountId: string;
   overrides?: Omit<SignalManagedNativeTransport, "kind">;
+  reserveTargetAccountPorts?: boolean;
 }): SignalManagedNativeTransport {
   const existing = resolveConfiguredSignalTransport(params.cfg, params.accountId);
   const existingManaged = existing?.kind === "managed-native" ? existing : undefined;
@@ -221,7 +222,7 @@ export function prepareSignalManagedNativeTransport(params: {
   const targetAccountId = normalizeAccountId(params.accountId);
   const reservedPorts = new Set<number>();
   for (const [accountId, accountPorts] of portsByAccountId) {
-    if (accountId === targetAccountId) {
+    if (accountId === targetAccountId && !params.reserveTargetAccountPorts) {
       continue;
     }
     for (const httpPort of accountPorts) {