An administrator recently Implemented multi-factor authentication (MFA) with a standard security level selectee.

A session security level is a setting that determines how secure a user’s session is based on factors such as their login method, their IP address, their browser, or their device. Administrators can configure different session security levels for different user profiles and assign different actions or permissions to each session security level.

Multi-factor authentication (MFA) is a feature that requires users to verify their identity using two or more factors of authentication when they log in to Salesforce, such as their username and password plus a verification code or an app-generated token. MFA can enhance the security of user sessions and prevent unauthorized access.

If an administrator recently implemented MFA with a standard security level selected and is receiving cases that users are unable to log in, they should check the session security level required at login on the user profile. This setting determines what session security level users need to have when they log in based on their profile. If this setting is higher than the standard security level, users may not be able to log in with MFA alone and may need additional factors of authentication. References: https://help.salesforce.com/s/articleView?id=sf.security_sessions.htm &type=5 https://help.salesforce.com/s/articleView?id=sf.identity_mfa.htm &type=5