What happens if there are more than five unsuccessful attempts to enter the confirmation code...

In Veeam Backup & Replication, if there are multiple unsuccessful attempts to enter a confirmation code for Multi-Factor Authentication (MFA), the system will lock the user account to prevent unauthorized access. Based on standard security practices, and while it may vary, a lockout for 24 hours after exceeding the maximum number of failed attempts is a common approach to protect against brute force attacks. Please note that specific lockout policies can vary by system configuration and the policies set by the system administrator. It's always best to consult the actual system settings or documentation for the precise behavior in a given environment.