Based on the information you have provided, it may have been both a Norton error (ie. not being able to detect the existing vault) and User mistake.
- If a vault was not detected = Create a new password (“It asked me to add a Vault password, which I did.”)
- If a vault was detected = Unlock Your Vault prompt (enter existing Master Password)
As
Norton does not support multiple vaults, the outcome is self-explanatory.
Source:
Create Norton Password Manager cloud vault
We can immediately rule out Apple from the equation, as no amount of iCloud app data backup would restore the data which were stored on Norton servers. Norton Password Manager does not create local vaults.
Source:
What does iCloud back up?
Norton customers should reach out to Norton Support for future advice about managing your passwords on Norton services.