What can cause users to be prompted for unrecognized MFA factors, such as a wrong...

When users are prompted for unrecognized MFA factors, it is often due to a discrepancy between the identity information they are providing and the information registered in the MFA system. If a user mistypes their username, the system may not recognize them and therefore prompt them with MFA challenges that are not associated with their account. This is a common security measure to prevent unauthorized access.

References: This explanation is based on general principles of MFA systems and their operation. For the most accurate and detailed explanation, please refer to the official CyberArk Defender Access (ACC-DEF) study guide and course documentation, which can be found through the CyberArk training portal1.