diff --git a/docs/BUG_HISTORY.md b/docs/BUG_HISTORY.md
index cc8562ca..bbde5ab2 100644
--- a/docs/BUG_HISTORY.md
+++ b/docs/BUG_HISTORY.md
@@ -457,3 +457,19 @@
 - 相关记录：BUG-022、BUG-024、BUG-025
 - 复发自：无
 - 修复版本：待提交（production gate）
+
+## BUG-027 | 已完成的生时校正会话打开后误建新案例
+
+- 状态：resolved
+- 首次发现：2026-07-22
+- 最近更新：2026-07-22
+- 影响面：生时校正历史会话恢复、范围终态展示、首页继续入口与计费
+- 用户现象：范围校正完成后刷新，点击侧边栏原会话会卡在“正在建立校正记录”，或跳到另一个会话并提示加载最新进度；首页同时重新显示开始入口。
+- 触发条件：已绑定 case 的生时校正会话对应 `completed`/`abandoned` 终态，而账户接口只投影当前未完成 case；或者账户另有一个更新的未完成 case。
+- 根因：会话打开逻辑只按账户当前 case 决定 resume/start，没有优先恢复所点击会话自己的 `rectificationCaseId`；历史终态加载后又会覆盖账户当前可恢复 case，异步账户刷新还拒绝接受 `null` 或另一个最新 case。
+- 修复：已绑定的生时校正会话始终以自身 case id 执行只读 resume；只有首页或未绑定会话才按账户当前 case 复用或创建；历史终态不再覆盖另一个未完成 case，终态后账户刷新接受服务端最新投影。
+- 验证：入口契约测试锁定历史会话按自身 case 恢复、首页重新校正仍创建独立会话，以及历史终态不覆盖当前未完成 case；发布后用 production 合成账号复查范围终态、刷新恢复、首页入口与余额不变量。
+- 防复发：聊天会话的 `rectificationCaseId` 是历史查看的第一绑定键；账户 `rectificationCase` 只代表当前未完成案例，二者不得相互替代。
+- 相关记录：BUG-017、BUG-019、BUG-020
+- 复发自：无
+- 修复版本：待提交（production gate）
diff --git a/frontend/src/app/page.tsx b/frontend/src/app/page.tsx
index 3eb02dc7..afd4782c 100644
--- a/frontend/src/app/page.tsx
+++ b/frontend/src/app/page.tsx
@@ -1913,18 +1913,27 @@ export default function Home() {
       rectificationCase: account.rectificationCase,
       hasConfirmedBirthTime: account.hasConfirmedBirthTime,
     });
-    const resumableSession = action === "resume" && account.rectificationCase
+    const sourceBoundCaseId = sourceSession.sessionType === "birth_time_rectification"
+      ? sourceSession.rectificationCaseId
+      : null;
+    const accountResumeCase = action === "resume" ? account.rectificationCase : null;
+    const resumeTarget = sourceBoundCaseId
+      ? {
+          caseId: sourceBoundCaseId,
+          turnVersion: accountResumeCase?.caseId === sourceBoundCaseId
+            ? accountResumeCase.turnVersion
+            : 0,
+        }
+      : accountResumeCase;
+    const resumableSession = !sourceBoundCaseId && accountResumeCase
       ? sessions.find((session) => session.sessionType === "birth_time_rectification"
-        && session.rectificationCaseId === account.rectificationCase?.caseId)
+        && session.rectificationCaseId === accountResumeCase.caseId)
         ?? sessions.find((session) => session.sessionType === "birth_time_rectification"
           && session.rectificationCaseId === null)
         ?? null
       : null;
-    const canReuseSourceRectificationSession = action === "resume"
-      && sourceSession.sessionType === "birth_time_rectification"
-      && account.rectificationCase !== null
-      && (sourceSession.rectificationCaseId === account.rectificationCase.caseId
-        || sourceSession.rectificationCaseId === null);
+    const canReuseSourceRectificationSession = sourceSession.sessionType === "birth_time_rectification"
+      && (sourceBoundCaseId !== null || accountResumeCase !== null);
     const rectificationSession = canReuseSourceRectificationSession
       ? sourceSession
       : resumableSession ?? createSession(modelCatalog.defaultModelId, "birth_time_rectification");
@@ -1957,7 +1966,7 @@ export default function Home() {
     setActiveSessionId(rectificationSession.id);
     try {
       let turn: ConversationalRectificationTurn;
-      if (action !== "resume" || !account.rectificationCase) {
+      if (!resumeTarget) {
         const durable = await durableRectificationQuestionHandoff.current.load();
         turn = durable && durable.status !== "consumed"
           ? durable.turn
@@ -1967,8 +1976,10 @@ export default function Home() {
               pendingConsultationQuestion: requestedQuestion,
             });
       } else {
-        let current = account.rectificationCase;
-        if (pendingConsultationQuestion) {
+        let current = resumeTarget;
+        const canAttachQuestion = pendingConsultationQuestion
+          && accountResumeCase?.caseId === current.caseId;
+        if (canAttachQuestion) {
           try {
             turn = await durableRectificationQuestionHandoff.current.attach({
               caseId: current.caseId,
@@ -2063,16 +2074,22 @@ export default function Home() {
       ...current,
       hasConfirmedBirthTime: current.hasConfirmedBirthTime
         || (turn.status === "completed" && turn.candidate.status === "confirmed"),
-      rectificationCase: {
-        caseId: turn.caseId,
-        journeyProtocol: "conversational-evidence-v3",
-        status: turn.status,
-        turnVersion: turn.turnVersion,
-        isRevision: current.rectificationCase?.isRevision
-          ?? current.hasConfirmedBirthTime,
-        preservesActiveTime: current.rectificationCase?.preservesActiveTime
-          ?? current.hasConfirmedBirthTime,
-      },
+      rectificationCase: ["active", "paused", "confirming"].includes(turn.status)
+        ? {
+            caseId: turn.caseId,
+            journeyProtocol: "conversational-evidence-v3",
+            status: turn.status,
+            turnVersion: turn.turnVersion,
+            isRevision: current.rectificationCase?.caseId === turn.caseId
+              ? current.rectificationCase.isRevision
+              : current.hasConfirmedBirthTime,
+            preservesActiveTime: current.rectificationCase?.caseId === turn.caseId
+              ? current.rectificationCase.preservesActiveTime
+              : current.hasConfirmedBirthTime,
+          }
+        : current.rectificationCase?.caseId === turn.caseId
+          ? null
+          : current.rectificationCase,
     } : current);
     if (turn.status === "completed"
       && turn.candidate.status === "confirmed"
@@ -2094,6 +2111,7 @@ export default function Home() {
       .then((latest) => {
         if (!accountRefreshGuard.current.isCurrent(requestIdentity)) return;
         setAccount((current) => {
+          if (turn.status === "completed" || turn.status === "abandoned") return latest;
           if (latest.rectificationCase?.caseId !== turn.caseId
             || latest.rectificationCase.turnVersion < turn.turnVersion) return current;
           return latest;
diff --git a/frontend/tests/consultation-entrypoint.test.ts b/frontend/tests/consultation-entrypoint.test.ts
index 04c775f1..8722653c 100644
--- a/frontend/tests/consultation-entrypoint.test.ts
+++ b/frontend/tests/consultation-entrypoint.test.ts
@@ -149,21 +149,33 @@ test("homepage reuses the session bound to an unfinished rectification case", ()
   const end = source.indexOf("function handleConversationalRectificationTurn", start);
   const handler = source.slice(start, end);
 
-  assert.match(handler, /action === "resume" && account\.rectificationCase/);
-  assert.match(handler, /session\.rectificationCaseId === account\.rectificationCase\?\.caseId/);
+  assert.match(handler, /const accountResumeCase = action === "resume" \? account\.rectificationCase : null/);
+  assert.match(handler, /session\.rectificationCaseId === accountResumeCase\.caseId/);
   assert.match(handler, /resumableSession \?\? createSession/);
 });
 
-test("starting again after a completed rectification creates a new dedicated session", () => {
+test("a bound rectification session resumes its own case while a homepage restart stays dedicated", () => {
   const source = readFileSync(new URL("../src/app/page.tsx", import.meta.url), "utf8");
   const start = source.indexOf("async function openBirthTimeRectification");
   const end = source.indexOf("function handleConversationalRectificationTurn", start);
   const handler = source.slice(start, end);
 
-  assert.match(handler, /const canReuseSourceRectificationSession = action === "resume"/);
-  assert.match(handler, /sourceSession\.rectificationCaseId === account\.rectificationCase\.caseId/);
+  assert.match(handler, /const sourceBoundCaseId = sourceSession\.sessionType === "birth_time_rectification"/);
+  assert.match(handler, /const resumeTarget = sourceBoundCaseId/);
+  assert.match(handler, /caseId: sourceBoundCaseId/);
+  assert.match(handler, /if \(!resumeTarget\) \{[\s\S]*?type: "start"/);
   assert.match(handler, /const rectificationSession = canReuseSourceRectificationSession[\s\S]*?: resumableSession \?\? createSession/);
-  assert.doesNotMatch(handler, /const rectificationSession = sourceSession\.sessionType === "birth_time_rectification"/);
+  assert.match(handler, /type: "resume",[\s\S]*?caseId: current\.caseId/);
+});
+
+test("historical completed rectification does not replace the account's unfinished case", () => {
+  const source = readFileSync(new URL("../src/app/page.tsx", import.meta.url), "utf8");
+  const start = source.indexOf("function handleConversationalRectificationTurn");
+  const end = source.indexOf("async function draftSynastryQuestionFromChart", start);
+  const handler = source.slice(start, end);
+
+  assert.match(handler, /current\.rectificationCase\?\.caseId === turn\.caseId[\s\S]*?\? null[\s\S]*?: current\.rectificationCase/);
+  assert.match(handler, /turn\.status === "completed" \|\| turn\.status === "abandoned"\) return latest/);
 });
 
 test("rectify-first suggestions hand the source question to a dedicated rectification session", () => {