Your password might be displayed instead of your password hint if you used the Add APFS Volume command in Disk Utility to create an encrypted APFS volume, and you supplied a password hint.

Changing the password on an affected volume clears the hint but doesn’t affect the underlying encryption keys that protect the data.

Apple recommends that you take these steps to guard the security of your data.

Encrypted APFS volumes that you created using any other method are not affected.