1. Update your device to the latest software version: Software updates often include bug fixes and performance improvements, so it's always a good idea to make sure that your device is running the latest version of iOS or iPadOS. To check for updates, go to "Settings" > "General" > "Software Update."
2. Check your iCloud Keychain settings: iCloud Keychain is a feature that allows you to securely store your passwords and credit card information across all of your devices. Make sure that iCloud Keychain is turned on in your device's settings by going to "Settings" > "Passwords & Accounts" > "Website & App Passwords."
3. Reset your device's settings: Resetting your device's settings can sometimes help to resolve problems with password syncing. This will reset your device's settings to their default values, but will not delete any data or media. To do this, go to "Settings" > "General" > "Reset" > "Reset All Settings."
If none of these steps resolve the issue, it's possible that there may be a more serious problem with your device's software. In this case, you may want to contact Apple Support or visit an authorized service provider for further assistance.