1, Apple's screen lock password cannot be changed to 4 digits because there is no password option set or applepay is bound to a bank card. Users can set and remove the wallet app through the password options page.

2. Case-insensitive. After setting applepay, the password for screen locking has changed, because the password is case-insensitive, and applepay's screen locking error tolerance rate is low, so it can't recognize uppercase and can only enter lowercase. Just change it to lowercase password.

3. If you can't set a 4-digit password: In iOS 13 and newer systems, Apple has increased the security of ApplePay. When users have enabled the ApplePay function and added a bank card, they need to use a more secure password (at least 6 digits), which cannot be set as a 4-digit password.

4. This is normal. After setting the applepay password, the screen lock password will be automatically changed, and the screen lock password will become the password of applepay. The user can unlock the mobile phone by entering the payment password. Introduction to ApplePay ApplePay is a NFC-based mobile payment function launched by Apple.