If your Reach database is controlled by the data sync with your school system, students who are not identified as students in the system will be archived from Reach with every sync update. Note that the student's parents will also be archived in Reach. However, you can set the student profiles or parent profiles to NOT be managed by the data sync.
If you have temporary students, for example, then you can add them manually and set their profile to NOT be manage by your data sync. This will ensure that they're not archived in your Reach database when they are not confirmed as students by your school system data sync. You can also use this method if you do not want the status or data in a contact's profile to be updated automatically by the regular data sync.
- If you have manually entered the student details already into Reach and discovered them to have disappeared from People Management, then they have most likely been archived so you need to recover the student and parents from the deleted list.
See Deleting Contacts and recovering deleted contacts in REACH - Once recovered or added manually to the system, you then need to ensure that the Student and Parents are set to NOT be managed by your data sync. In the contact profiles > Security Tab set the Field "Managed by Sync" to NO.
- Be sure to save changes to each user's profile to ensure setting update applies.

NOTE that this is only required if the student is NOT going to be flagged as a boarder in your school system database.