First, please note that this app's iCloud backup is not an automatic sync. You need to run the backup and restore manually.
Here is how it works: on the device you want to copy data from, run "Create Backup".
Then, on the device you want to bring the data to, run "Restore from Backup".
This synchronizes your data.
If it does not work, please check the following:
- Open the "Settings" app, tap your name at the top (your Apple Account), then tap "iCloud", and make sure you have enough free iCloud storage.
- Make sure your iPhone itself has enough free storage. Open the "Settings" app, tap "General", then "iPhone Storage" (or "iPad Storage") to check the available space. This app's storage usage is also shown in the list; you need roughly the same amount of free space. You can free up space by enabling iCloud Photos or deleting unused apps.
- Make sure the app is updated to the latest version on both devices.
- Try deleting the iCloud backup once, creating it again, and then tapping "Restore from Backup".
- Restart your device and try again.
- Open the "Settings" app, tap your name at the top, tap "iCloud", and turn off "iCloud Drive". Then turn it back on, wait 5 minutes, reopen the app, and check the iCloud Backup screen.
If none of these steps work, we are sorry for the trouble, but please tap the "Contact Us" button at the top right and tell us exactly where the process fails.
We will reply with a solution for your case.
Thank you.