Starting from RIO version 3.20, a new field — Attendance Submission — has been introduced in the Session object to allow administrators to define whether all students’ attendance must be taken when a faculty member saves changes in the Attendance Wizard. 

The default value should be set to "Allow Partial" to ensure that existing customers are not affected when new session records are created after the upgrade. This can be configured at the Record Types: Class / Standalone / Template

However, customers can change the value to "Require All" for specific sessions if needed.