Just to check, when you say “device” you are referring to a macOS device (e.g. iMac)?
When you deleted the app, did you delete the preferences file as well? That might be worth a shot. No need to delete the app again.
As I have no idea how much of an experienced user you are, I’ll give you full instructions:
- Go to the Finder.
- Go to the Go menu.
- With the menu open, hold down Option and then click on the Library option which appears.
- A Finder window opens. Find the Preferences folder within there.
- In that folder, move com.apple.iWork.Pages.plist to the Trash. (You may have a lot of files to search through; a search for “pages” will show you what you need.)