Missing items Issue - iCloud

Please read the whole article before doing anything.

1) Could you check your synchronization settings, please?

Make sure your iCloud synchronization method is well set on the category you want to be synchronized with.

- Edit your category:
• On iOS: go to the categories screen, touch the pencil button at the top left corner of the screen and touch the category you want to edit.
• On macOS: right click on the category and click on "Edit".
• On Android: click on the category name, click on "Modify categories" and touch the category you want to edit.
- Choose iCloud as the synchronization method.

2) If the categories you want to synchronize were already well set, you can follow these next steps:

- Please, make a backup of your data.
- Then, on one device at a time:
• Deactivate the synchronization option (Settings > Synchronization)
• A warning message pops up: choose "Remove categories"
• All the categories linked to iCloud will disappear.
- Then:
• Reactivate iCloud in the settings (Settings > Synchronization)
• Check if it's all fixed for the categories with which you had the issue.