I Was Filming a Demo of My Monitoring Tool. The Monitor Wasn't Monitoring.

A Cloudflare Worker using Sentry.withMonitor() was running on schedule but not creating a Sentry Cron monitor or check-ins.

The issue was that the monitor lacked explicit cron settings, so the job executed while monitoring silently failed.

After adding the cron schedule, check-in margin, max runtime, and timezone, the monitor appeared correctly in Sentry.

The case shows that successful execution does not guarantee observability, and Sentry Cron monitors need explicit scheduling to work.