Akindi assumes each student ID is unique across all courses. So, if you use ID 21 for two different students in two different courses, Akindi will use one of those names for all students with ID 21.
We recommend assigning students IDs which are a combination of the school year, semester, and period or course number to make sure they are unique. For example, students in a first period (01) course in the second semester (02) of 2015 (15) might be assigned the IDs 15020101 through 15020135. Student IDs can be up to 9 digits long.