Orphaned classes can be a result of suspending or deleting a teachers google account.

If a leaving teacher owns classes, it’s recommended that you transfer ownership of those classes to another teacher or a placeholder account (maybe your admin user?) This will prevent classes from becoming Orphaned (locked) where users cannot access or manage a class

Just add another teacher to the group in smartadmin and set the new teacher to be the “Main Teacher” Hit save and the Classroom Owner will become that new teacher.

Here is a helpful guide explaining the Orphaned issue in detail and how to avoid it.

https://realsmart.groovehq.com/help/orphaned-classes-in-google-classroom