Backed up from iCloud or iTunes?
About your Messages and Voice Memos data after restore from iCloud
With Messages in iCloud and Voice Memos in iCloud*, your text messages and voice recordings automatically upload to iCloud. They aren’t included in your backup. After you restore your device from iCloud Backup, stay connected to Wi-Fi so that your text messages and voice recordings can download.
If you turn off Messages in iCloud, your text messages and attachments no longer upload automatically, but they save in your next iCloud Backup and download in the background when you restore. Stay connected to Wi-Fi until the process finishes. The time it takes to restore depends on the size of your backup and the speed of your Wi-Fi.
Sometimes, if you restore a device from a backup of another kind of device, your Messages and Voice Memos won’t restore. For example, if you use an iPad backup to restore an iPhone, your Messages and Voice Memos may not appear on the iPhone.
If your information is still missing after you restore, you can try to restore from a different iCloud or iTunes backup. Always back up your current data in iTunes before you try to restore from iCloud Backup.
*If you use iOS 11 or earlier, or macOS High Sierra or earlier, your Voice Memos are included in iCloud Backup, not iCloud.
Information about products not manufactured by Apple, or independent websites not controlled or tested by Apple, is provided without recommendation or endorsement. Apple assumes no responsibility with regard to the selection, performance, or use of third-party websites or products. Apple makes no representations regarding third-party website accuracy or reliability. Risks are inherent in the use of the Internet. Contact the vendor for additional information. Other company and product names may be trademarks of their respective owners.
About missing information after you restore your iOS device with ...
https://support.apple.com/en-us/HT203768
