diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9387f5a94ce..ace9d907b27 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -71,6 +71,7 @@ Docs: https://docs.openclaw.ai
 - Agents/Claude: treat zero-token empty `stop` turns as failed provider output,
   retry once, repair replay, and allow configured model fallback instead of
   preserving them as successful silent replies. Fixes #71880. Thanks @MagnaAI.
+- Tasks: normalize task lifecycle timestamps at create, update, and restore time, and report retained lost tasks as audit warnings until their cleanup window expires. (#71871) Thanks @likewen-tech.
 - Diagnostics/OTEL: treat normal early model stream cleanup as a completed model call instead of exporting a misleading `StreamAbandoned` error span. Thanks @vincentkoc.
 - Gateway/pairing: stop corrupt or unreadable device/node pairing stores from being treated as empty state, preserving `paired.json` for repair instead of overwriting approved pairings. Fixes #71873. Thanks @iret77.
 - ACP: keep `/acp` management commands, plus local `/status` and `/unfocus`, on the Gateway path inside ACP-bound threads so they are not consumed as ACP prompt text. Fixes #66298. Thanks @kindomLee.
diff --git a/docs/automation/tasks.md b/docs/automation/tasks.md
index 73c567ace40..686cfc057ab 100644
--- a/docs/automation/tasks.md
+++ b/docs/automation/tasks.md
@@ -194,14 +194,14 @@ openclaw tasks audit [--json]
 
 Surfaces operational issues. Findings also appear in `openclaw status` when issues are detected.
 
-| Finding                   | Severity | Trigger                                               |
-| ------------------------- | -------- | ----------------------------------------------------- |
-| `stale_queued`            | warn     | Queued for more than 10 minutes                       |
-| `stale_running`           | error    | Running for more than 30 minutes                      |
-| `lost`                    | error    | Runtime-backed task ownership disappeared             |
-| `delivery_failed`         | warn     | Delivery failed and notify policy is not `silent`     |
-| `missing_cleanup`         | warn     | Terminal task with no cleanup timestamp               |
-| `inconsistent_timestamps` | warn     | Timeline violation (for example ended before started) |
+| Finding                   | Severity   | Trigger                                                                                                      |
+| ------------------------- | ---------- | ------------------------------------------------------------------------------------------------------------ |
+| `stale_queued`            | warn       | Queued for more than 10 minutes                                                                              |
+| `stale_running`           | error      | Running for more than 30 minutes                                                                             |
+| `lost`                    | warn/error | Runtime-backed task ownership disappeared; retained lost tasks warn until `cleanupAfter`, then become errors |
+| `delivery_failed`         | warn       | Delivery failed and notify policy is not `silent`                                                            |
+| `missing_cleanup`         | warn       | Terminal task with no cleanup timestamp                                                                      |
+| `inconsistent_timestamps` | warn       | Timeline violation (for example ended before started)                                                        |
 
 ### `tasks maintenance`
 
@@ -284,7 +284,7 @@ The registry loads into memory at gateway start and syncs writes to SQLite for d
 A sweeper runs every **60 seconds** and handles three things:
 
 1. **Reconciliation** — checks whether active tasks still have authoritative runtime backing. ACP/subagent tasks use child-session state, cron tasks use active-job ownership, and chat-backed CLI tasks use the owning run context. If that backing state is gone for more than 5 minutes, the task is marked `lost`.
-2. **Cleanup stamping** — sets a `cleanupAfter` timestamp on terminal tasks (endedAt + 7 days).
+2. **Cleanup stamping** — sets a `cleanupAfter` timestamp on terminal tasks (endedAt + 7 days). During retention, lost tasks still appear in audit as warnings; after `cleanupAfter` expires or when cleanup metadata is missing, they are errors.
 3. **Pruning** — deletes records past their `cleanupAfter` date.
 
 **Retention**: terminal task records are kept for **7 days**, then automatically pruned. No configuration needed.
diff --git a/docs/cli/tasks.md b/docs/cli/tasks.md
index fdc76d1bc3e..58ea07f9730 100644
--- a/docs/cli/tasks.md
+++ b/docs/cli/tasks.md
@@ -75,7 +75,7 @@ Cancels a running background task.
 openclaw tasks audit [--severity <warn|error>] [--code <name>] [--limit <n>] [--json]
 ```
 
-Surfaces stale, lost, delivery-failed, or otherwise inconsistent task and Task Flow records.
+Surfaces stale, lost, delivery-failed, or otherwise inconsistent task and Task Flow records. Lost tasks retained until `cleanupAfter` are warnings; expired or unstamped lost tasks are errors.
 
 ### `maintenance`
 
diff --git a/src/tasks/task-registry.test.ts b/src/tasks/task-registry.test.ts
index 38aa881cb1b..51af5da44a9 100644
--- a/src/tasks/task-registry.test.ts
+++ b/src/tasks/task-registry.test.ts
@@ -1342,6 +1342,13 @@ describe("task-registry", () => {
         error: "backing session missing",
       });
       expect(getTaskById(task.taskId)?.cleanupAfter).toBeGreaterThan(now);
+      expect(getInspectableTaskAuditSummary()).toMatchObject({
+        errors: 0,
+        warnings: 1,
+        byCode: expect.objectContaining({
+          lost: 1,
+        }),
+      });
     });
   });
 
diff --git a/src/tasks/task-registry.ts b/src/tasks/task-registry.ts
index ad4d7101d30..fcab081ed73 100644
--- a/src/tasks/task-registry.ts
+++ b/src/tasks/task-registry.ts
@@ -181,6 +181,8 @@ function cloneTaskRecord(record: TaskRecord): TaskRecord {
 }
 
 function normalizeTaskTimestamps(task: TaskRecord): TaskRecord {
+  // Detached runtimes can report lifecycle times captured before the registry
+  // inserted or restored the row; keep createdAt as the visible lifecycle floor.
   let createdAt = task.createdAt;
   for (const candidate of [task.startedAt, task.lastEventAt, task.endedAt]) {
     if (typeof candidate === "number" && candidate < createdAt) {