[BUG] CronCreate jobs never fire in Claude Code Desktop app (works fine in CLI)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Job never fires at all in the Desktop app, in any of the 4 tested configurations across 2 separate days/sessions (2026-07-20 and 2026-07-21→22). CronList shows the job as alive/pending the whole time with no error. The exact same schedules fire normally when run from Claude Code CLI instead of Desktop.

What Should Happen?

Cron job fires at/near its scheduled time (per tool docs: recurring jobs may fire up to 10% of their period late, max 15 min).

Error Messages/Logs

None — this is a silent failure. No error message, no exception, no indication in CronList that anything went wrong. The job simply never fires.

Steps to Reproduce

1. In a Claude Code Desktop app session, call CronCreate with cron: "/5 *", recurring: true (session-only, no durable flag).
2. Confirm the job appears in CronList.
3. Leave the session running, including multi-hour stretches with no other activity (genuinely idle).
4. Observe: after 8+ hours, the job has never fired once. CronList still shows it as active/pending the whole time.
5. Same result was independently reproduced on a separate day (2026-07-20) using one-shot jobs instead (both wildcard-minute and a job pinned to an exact future time) — also never fired.
6. The exact same schedules, run from Claude Code CLI instead of Desktop, fire normally.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.215(ClaudeCode)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Ruled out "REPL never actually idle" as the cause — a background Monitor task was running concurrently in both Desktop sessions, initially suspected as the culprit, but the same schedule + concurrent Monitor combination fires normally in a CLI session, and one test included multi-hour stretches with zero incoming events (genuinely idle), so lack of idle time doesn't explain it.

Separately noticed: a one-shot job pinned to an exact date/time that gets missed silently rolls its "next match" forward to the same date next year, rather than surfacing as expired/failed. May or may not be related to the non-firing issue, but worth noting.

Related to #51296, which reported the exact same symptom (session-scoped CronCreate never firing on Desktop app, even when idle). That issue was auto-closed by github-actions for inactivity on 2026-05-27 ("Closing for now — inactive for too long. Please open a new issue if this is still relevant.") — not resolved by a maintainer. We independently reproduced the same behavior on 2026-07-20 and 2026-07-21→22, so it is still relevant.