diff --git a/CHANGELOG.md b/CHANGELOG.md
index a2877640b..a67f6817a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -41,6 +41,7 @@ Docs: https://docs.openclaw.ai
 - Security/BlueBubbles: reject ambiguous shared-path webhook routing when multiple webhook targets match the same guid/password.
 - Security/BlueBubbles: require explicit `mediaLocalRoots` allowlists for local outbound media path reads to prevent local file disclosure. (#16322) Thanks @mbelinky.
 - Cron/Slack: preserve agent identity (name and icon) when cron jobs deliver outbound messages. (#16242) Thanks @robbyczgw-cla.
+- Cron: repair missing/corrupt `nextRunAtMs` for the updated job without globally recomputing unrelated due jobs during `cron update`. (#15750)
 - Discord: prefer gateway guild id when logging inbound messages so cached-miss guilds do not appear as `guild=dm`. Thanks @thewilloftheshadow.
 - TUI: refactor searchable select list description layout and add regression coverage for ANSI-highlight width bounds.
 
diff --git a/src/cron/service.issue-regressions.test.ts b/src/cron/service.issue-regressions.test.ts
index 210f08987..44c50bc41 100644
--- a/src/cron/service.issue-regressions.test.ts
+++ b/src/cron/service.issue-regressions.test.ts
@@ -152,6 +152,84 @@ describe("Cron issue regressions", () => {
     await store.cleanup();
   });
 
+  it("repairs missing nextRunAtMs on non-schedule updates without touching other jobs", async () => {
+    const store = await makeStorePath();
+    const cron = new CronService({
+      cronEnabled: true,
+      storePath: store.storePath,
+      log: noopLogger,
+      enqueueSystemEvent: vi.fn(),
+      requestHeartbeatNow: vi.fn(),
+      runIsolatedAgentJob: vi.fn().mockResolvedValue({ status: "ok", summary: "ok" }),
+    });
+    await cron.start();
+
+    const created = await cron.add({
+      name: "repair-target",
+      schedule: { kind: "cron", expr: "0 * * * *", tz: "UTC" },
+      sessionTarget: "main",
+      payload: { kind: "systemEvent", text: "tick" },
+    });
+    const updated = await cron.update(created.id, {
+      payload: { kind: "systemEvent", text: "tick-2" },
+      state: { nextRunAtMs: undefined },
+    });
+
+    expect(updated.payload.kind).toBe("systemEvent");
+    expect(typeof updated.state.nextRunAtMs).toBe("number");
+    expect(updated.state.nextRunAtMs).toBe(created.state.nextRunAtMs);
+
+    cron.stop();
+    await store.cleanup();
+  });
+
+  it("does not advance unrelated due jobs when updating another job", async () => {
+    const store = await makeStorePath();
+    const now = Date.parse("2026-02-06T10:05:00.000Z");
+    vi.setSystemTime(now);
+    const cron = new CronService({
+      cronEnabled: false,
+      storePath: store.storePath,
+      log: noopLogger,
+      enqueueSystemEvent: vi.fn(),
+      requestHeartbeatNow: vi.fn(),
+      runIsolatedAgentJob: vi.fn().mockResolvedValue({ status: "ok", summary: "ok" }),
+    });
+    await cron.start();
+
+    const dueJob = await cron.add({
+      name: "due-preserved",
+      schedule: { kind: "every", everyMs: 60_000, anchorMs: now },
+      sessionTarget: "main",
+      payload: { kind: "systemEvent", text: "due-preserved" },
+    });
+    const otherJob = await cron.add({
+      name: "other-job",
+      schedule: { kind: "cron", expr: "0 * * * *", tz: "UTC" },
+      sessionTarget: "main",
+      payload: { kind: "systemEvent", text: "other" },
+    });
+
+    const originalDueNextRunAtMs = dueJob.state.nextRunAtMs;
+    expect(typeof originalDueNextRunAtMs).toBe("number");
+
+    // Make dueJob past-due without running timer callbacks.
+    vi.setSystemTime(now + 5 * 60_000);
+
+    await cron.update(otherJob.id, {
+      payload: { kind: "systemEvent", text: "other-updated" },
+    });
+
+    const storeData = JSON.parse(await fs.readFile(store.storePath, "utf8")) as {
+      jobs: Array<{ id: string; state?: { nextRunAtMs?: number } }>;
+    };
+    const persistedDueJob = storeData.jobs.find((job) => job.id === dueJob.id);
+    expect(persistedDueJob?.state?.nextRunAtMs).toBe(originalDueNextRunAtMs);
+
+    cron.stop();
+    await store.cleanup();
+  });
+
   it("caps timer delay to 60s for far-future schedules", async () => {
     const timeoutSpy = vi.spyOn(globalThis, "setTimeout");
     const store = await makeStorePath();
diff --git a/src/cron/service/ops.ts b/src/cron/service/ops.ts
index 982a09e88..4a2d02f42 100644
--- a/src/cron/service/ops.ts
+++ b/src/cron/service/ops.ts
@@ -119,7 +119,7 @@ export async function add(state: CronServiceState, input: CronJobCreate) {
 export async function update(state: CronServiceState, id: string, patch: CronJobPatch) {
   return await locked(state, async () => {
     warnIfDisabled(state, "update");
-    await ensureLoaded(state);
+    await ensureLoaded(state, { skipRecompute: true });
     const job = findJobOrThrow(state, id);
     const now = state.deps.nowMs();
     applyJobPatch(job, patch);
@@ -150,6 +150,13 @@ export async function update(state: CronServiceState, id: string, patch: CronJob
         job.state.nextRunAtMs = undefined;
         job.state.runningAtMs = undefined;
       }
+    } else if (job.enabled) {
+      // Non-schedule edits should not mutate other jobs, but still repair a
+      // missing/corrupt nextRunAtMs for the updated job.
+      const nextRun = job.state.nextRunAtMs;
+      if (typeof nextRun !== "number" || !Number.isFinite(nextRun)) {
+        job.state.nextRunAtMs = computeJobNextRunAtMs(job, now);
+      }
     }
 
     await persist(state);