diff --git a/CHANGELOG.md b/CHANGELOG.md
index a5a4e5aefd2..1c519affc4c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@ Docs: https://docs.openclaw.ai
 
 - Windows/Plugin install: avoid `spawn EINVAL` on Windows npm/npx invocations by resolving to `node` + npm CLI scripts instead of spawning `.cmd` directly. Landed from contributor PR #31147 by @codertony. Thanks @codertony.
 - LINE/Voice transcription: classify M4A voice media as `audio/mp4` (not `video/mp4`) by checking the MPEG-4 `ftyp` major brand (`M4A ` / `M4B `), restoring voice transcription for LINE voice messages. Landed from contributor PR #31151 by @scoootscooob. Thanks @scoootscooob.
+- Cron/Delivery mode none: send explicit `delivery: { mode: "none" }` from cron editor for both add and update flows so previous announce delivery is actually cleared. Landed from contributor PR #31145 by @byungsker. Thanks @byungsker.
 - Agents/Thinking fallback: when providers reject unsupported thinking levels without enumerating alternatives, retry with `think=off` to avoid hard failure during model/provider fallback chains. Landed from contributor PR #31002 by @yfge. Thanks @yfge.
 - Agents/Failover reason classification: avoid false rate-limit classification from incidental `tpm` substrings by matching TPM as a standalone token/phrase and keeping auth-context errors on the auth path. Landed from contributor PR #31007 by @HOYALIM. Thanks @HOYALIM.
 - Slack/Announce target account routing: enable session-backed announce-target lookup for Slack so multi-account announces resolve the correct `accountId` instead of defaulting to bot-token context. Landed from contributor PR #31028 by @taw0002. Thanks @taw0002.
diff --git a/ui/src/ui/controllers/cron.test.ts b/ui/src/ui/controllers/cron.test.ts
index d8e55589360..50bdf5811fc 100644
--- a/ui/src/ui/controllers/cron.test.ts
+++ b/ui/src/ui/controllers/cron.test.ts
@@ -119,6 +119,91 @@ describe("cron controller", () => {
     });
   });
 
+  it('sends delivery: { mode: "none" } explicitly in cron.add payload', async () => {
+    const request = vi.fn(async (method: string, _payload?: unknown) => {
+      if (method === "cron.add") {
+        return { id: "job-none-add" };
+      }
+      if (method === "cron.list") {
+        return { jobs: [] };
+      }
+      if (method === "cron.status") {
+        return { enabled: true, jobs: 0, nextWakeAtMs: null };
+      }
+      return {};
+    });
+
+    const state = createState({
+      client: {
+        request,
+      } as unknown as CronState["client"],
+      cronForm: {
+        ...DEFAULT_CRON_FORM,
+        name: "none delivery job",
+        scheduleKind: "every",
+        everyAmount: "1",
+        everyUnit: "minutes",
+        sessionTarget: "isolated",
+        wakeMode: "next-heartbeat",
+        payloadKind: "agentTurn",
+        payloadText: "run this",
+        deliveryMode: "none",
+      },
+    });
+
+    await addCronJob(state);
+
+    const addCall = request.mock.calls.find(([method]) => method === "cron.add");
+    expect(addCall).toBeDefined();
+    expect((addCall?.[1] as { delivery?: unknown } | undefined)?.delivery).toEqual({
+      mode: "none",
+    });
+  });
+
+  it('sends delivery: { mode: "none" } explicitly in cron.update patch', async () => {
+    const request = vi.fn(async (method: string, _payload?: unknown) => {
+      if (method === "cron.update") {
+        return { id: "job-none-update" };
+      }
+      if (method === "cron.list") {
+        return { jobs: [{ id: "job-none-update" }] };
+      }
+      if (method === "cron.status") {
+        return { enabled: true, jobs: 1, nextWakeAtMs: null };
+      }
+      return {};
+    });
+
+    const state = createState({
+      client: {
+        request,
+      } as unknown as CronState["client"],
+      cronEditingJobId: "job-none-update",
+      cronForm: {
+        ...DEFAULT_CRON_FORM,
+        name: "switch to none",
+        scheduleKind: "every",
+        everyAmount: "30",
+        everyUnit: "minutes",
+        sessionTarget: "isolated",
+        wakeMode: "next-heartbeat",
+        payloadKind: "agentTurn",
+        payloadText: "do work",
+        deliveryMode: "none",
+      },
+    });
+
+    await addCronJob(state);
+
+    const updateCall = request.mock.calls.find(([method]) => method === "cron.update");
+    expect(updateCall).toBeDefined();
+    expect(
+      (updateCall?.[1] as { patch?: { delivery?: unknown } } | undefined)?.patch?.delivery,
+    ).toEqual({
+      mode: "none",
+    });
+  });
+
   it("does not submit stale announce delivery when unsupported", async () => {
     const request = vi.fn(async (method: string, _payload?: unknown) => {
       if (method === "cron.add") {
@@ -159,8 +244,13 @@ describe("cron controller", () => {
     expect(addCall?.[1]).toMatchObject({
       name: "main job",
     });
-    expect((addCall?.[1] as { delivery?: unknown } | undefined)?.delivery).toBeUndefined();
-    expect(state.cronForm.deliveryMode).toBe("none");
+    // Delivery is explicitly sent as { mode: "none" } to clear the announce delivery on the backend.
+    // Previously this was sent as undefined, which left announce in place (bug #31075).
+    expect((addCall?.[1] as { delivery?: unknown } | undefined)?.delivery).toEqual({
+      mode: "none",
+    });
+    // After submit, form is reset to defaults (deliveryMode = "announce" from DEFAULT_CRON_FORM).
+    expect(state.cronForm.deliveryMode).toBe("announce");
   });
 
   it("submits cron.update when editing an existing job", async () => {
diff --git a/ui/src/ui/controllers/cron.ts b/ui/src/ui/controllers/cron.ts
index 16d84c1933f..79417fbfe04 100644
--- a/ui/src/ui/controllers/cron.ts
+++ b/ui/src/ui/controllers/cron.ts
@@ -614,20 +614,18 @@ export async function addCronJob(state: CronState) {
     const payload = buildCronPayload(form);
     const selectedDeliveryMode = form.deliveryMode;
     const delivery =
-      selectedDeliveryMode === "none"
-        ? state.cronEditingJobId
-          ? { mode: "none" as const }
-          : undefined
-        : selectedDeliveryMode
-          ? {
-              mode: selectedDeliveryMode,
-              channel:
-                selectedDeliveryMode === "announce"
-                  ? form.deliveryChannel.trim() || "last"
-                  : undefined,
-              to: form.deliveryTo.trim() || undefined,
-              bestEffort: form.deliveryBestEffort,
-            }
+      selectedDeliveryMode && selectedDeliveryMode !== "none"
+        ? {
+            mode: selectedDeliveryMode,
+            channel:
+              selectedDeliveryMode === "announce"
+                ? form.deliveryChannel.trim() || "last"
+                : undefined,
+            to: form.deliveryTo.trim() || undefined,
+            bestEffort: form.deliveryBestEffort,
+          }
+        : selectedDeliveryMode === "none"
+          ? ({ mode: "none" } as const)
           : undefined;
     const failureAlert = buildFailureAlert(form);
     const agentId = form.clearAgent ? null : form.agentId.trim();