Short answer: Check the last successful backup rather than assuming sync protects everything.
Try these steps
- Open your Apple Account settings and review iCloud Backup, or check the backup in Finder or Apple Devices if using a computer.
- Confirm the latest successful backup and the account or computer holding it.
- Review storage and connectivity if a backup has not completed; run a backup before replacing or resetting the phone.
When to ask for help
An incomplete backup may not contain recent data. Do not erase the old phone until important information is verified.
Learn more
Learn more: read this article — Back up iPhone with iCloud. Menu names and available features can vary by device, software version and account type.
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