diff --git a/background/steps/submit-signup-email.js b/background/steps/submit-signup-email.js
index b8cad06..2fd1839 100644
--- a/background/steps/submit-signup-email.js
+++ b/background/steps/submit-signup-email.js
@@ -85,6 +85,9 @@
       const reasonText = getErrorMessage(reasonMessage);
       const reasonSuffix = reasonText ? `（触发原因：${reasonText}）` : '';
       await addLog(`步骤 2：检测到当前会话已登录 ChatGPT，已跳过注册链路（步骤 3/4/5），将直接进入步骤 6。${reasonSuffix}`, 'warn');
+      const message = `姝ラ 2锛氭娴嬪埌褰撳墠鐣欏湪宸茬櫥褰?ChatGPT 棣栭〉锛屽凡闃绘鑷姩璺宠繃姝ラ 3/4/5銆傝鍏堟墽琛屾楠?1 娓呯悊浼氳瘽鍚庨噸璇曘€?${reasonSuffix}`;
+      await addLog(message, 'error');
+      throw new Error(message);
       await completeStepFromBackground(2, {
         email: resolvedEmail,
         nextSignupState: 'already_logged_in_home',
@@ -95,6 +98,19 @@
       return true;
     }
 
+    async function failStep2OnLoggedInSession(tabId, reasonMessage = '') {
+      const currentUrl = await getTabUrl(tabId);
+      if (!isLikelyLoggedInChatgptHomeUrl(currentUrl)) {
+        return false;
+      }
+
+      const reasonText = getErrorMessage(reasonMessage);
+      const reasonSuffix = reasonText ? `（触发原因：${reasonText}）` : '';
+      const message = `步骤 2：检测到当前停留在已登录 ChatGPT 首页，已阻止自动跳过步骤 3/4/5。请先执行步骤 1 清理会话后重试。${reasonSuffix}`;
+      await addLog(message, 'error');
+      throw new Error(message);
+    }
+
     async function submitSignupEmail(resolvedEmail, options = {}) {
       const {
         timeoutMs = 35000,
@@ -142,7 +158,7 @@
           signupTabId = (await ensureSignupAuthEntryPageReady(2)).tabId;
         } catch (entryError) {
           const entryErrorMessage = getErrorMessage(entryError);
-          if (await completeStep2AsLoggedInSession(signupTabId, resolvedEmail, entryErrorMessage)) {
+          if (await failStep2OnLoggedInSession(signupTabId, entryErrorMessage)) {
             return;
           }
           await addLog('步骤 2：切换认证入口失败，正在重新打开官网入口并重试提交邮箱...', 'warn');
@@ -170,7 +186,7 @@
           if (step2Result?.error) {
             const retryErrorMessage = getErrorMessage(step2Result.error);
             if (isSignupEntryUnavailableErrorMessage(retryErrorMessage)) {
-              if (await completeStep2AsLoggedInSession(signupTabId, resolvedEmail, retryErrorMessage)) {
+              if (await failStep2OnLoggedInSession(signupTabId, retryErrorMessage)) {
                 return;
               }
               await addLog('步骤 2：认证入口仍不可用，正在重新进入官网注册入口再重试一次...', 'warn');
@@ -198,7 +214,7 @@
         if (
           (isSignupEntryUnavailableErrorMessage(finalErrorMessage)
             || isRetryableStep2TransportErrorMessage(finalErrorMessage))
-          && await completeStep2AsLoggedInSession(signupTabId, resolvedEmail, finalErrorMessage)
+          && await failStep2OnLoggedInSession(signupTabId, finalErrorMessage)
         ) {
           return;
         }
diff --git a/tests/background-signup-step2-branching.test.js b/tests/background-signup-step2-branching.test.js
index 36729f1..55b7097 100644
--- a/tests/background-signup-step2-branching.test.js
+++ b/tests/background-signup-step2-branching.test.js
@@ -84,7 +84,7 @@ test('step 2 keeps password flow when landing on password page', async () => {
   ]);
 });
 
-test('step 2 falls back to already-logged-in branch when auth entry recovery fails on chatgpt home', async () => {
+test('step 2 stops with an explicit error instead of silently skipping 3/4/5 on chatgpt home', async () => {
   const completedPayloads = [];
   const logs = [];
 
@@ -117,10 +117,18 @@ test('step 2 falls back to already-logged-in branch when auth entry recovery fai
     SIGNUP_PAGE_INJECT_FILES: [],
   });
 
-  await executor.executeStep2({ email: 'user@example.com' });
+  await assert.rejects(
+    () => executor.executeStep2({ email: 'user@example.com' }),
+    /3\/4\/5/
+  );
 
-  assert.equal(completedPayloads.length, 1);
-  assert.deepStrictEqual(completedPayloads[0], {
+  assert.deepStrictEqual(completedPayloads, []);
+  assert.ok(logs.some((item) => /3\/4\/5/.test(item.message)));
+  return;
+  if (false) await executor.executeStep2({ email: 'user@example.com' });
+
+  if (false) assert.equal(completedPayloads.length, 1);
+  if (false) assert.deepStrictEqual(completedPayloads[0], {
     step: 2,
     payload: {
       email: 'user@example.com',