Check which kind of sync you set up
If you uploaded an ICS file, it's a snapshot. Later changes won't update the import. If you subscribed to a calendar URL in Outlook, the receiving app controls refresh timing; Microsoft says updates can sometimes take more than 24 hours. Confirm the method in Microsoft's subscription documentation.
If both accounts are simply visible in one app, there may be no copying process at all. Open the intended destination calendar by itself and look for the event there. For the difference, see sharing versus syncing.
For a Sync My Cal rule, inspect before repairing
- Check the pair. Confirm the source and destination accounts, calendar names, direction, and whether the rule is active. Identical calendar names can hide a wrong selection.
- Check the original. Is it inside the rule's date window? Is it all-day, declined, outside working hours, or excluded by a keyword, attendee, or duration filter?
- Run Test this rule. The dry run explains proposed changes and exclusions without writing copies. An intentionally excluded event doesn't need a repair.
- Read Activity and connection health. Follow any reconnection instruction for the affected account. The destination must remain writable.
- Use Sync now after fixing the cause. Check the native destination calendar again. Avoid repeatedly recreating the rule while an account still lacks permission.
Start with one short, timed test event that contains no sensitive details. That makes it easier to distinguish a general connection problem from a rule that excludes one particular meeting.
Check timing and which event you edited
Provider notifications trigger automatic updates, with a safety sweep every 15 minutes for missed or delayed notifications. These mechanisms don't establish a fixed delivery deadline. Check service status and the affected provider when a healthy rule is delayed.
Make changes on the original calendar. Editing a managed copy won't update its source. For a recurring meeting, check the affected occurrence and its time zone instead of assuming that every instance should change.
A copied event can't act as a relay. If A syncs to B and B syncs to C, an A event copied into B is excluded from B's source events. Add a direct A → C direction when C needs that availability.
Separate duplicates from overlapping views
Hide the source calendar in your calendar app. If the apparent duplicate disappears, you were seeing the original and its copy together. If both events remain on the destination, inspect whether another service or an older import created one of them.
Before switching tools, pause the old service and use its documented copy-removal process. Sync My Cal can manage its own tracked copies; don't assume it can identify every event another service created. Never bulk-delete original meetings to clear a sync problem.
Send a small, safe problem report
Use Contact Support with the providers involved, the intended direction, approximate time and time zone, the visible error, and whether a disposable test event reproduces it. Include the rule identifier if available.
Leave out access tokens, secret calendar feed URLs, guest lists, and confidential meeting notes. A description such as “timed Google event to Outlook, inside the date window, dry run shows excluded by working hours” is much more useful than a screenshot of an entire private calendar.