Can't add pending students.

I have 4 students in one class and one in the other  who are on the "pending students" list but not assigned to either class.  The kids have been logging in using their school district Clever account, but are not getting added to my classes. All of the help pages I've found say that should happen automatically.  I tried copying the class code to send them, but just got a message saying they'll be added when they sign up to KA.  They have, and they aren't getting added.

Does anyone know how to fix this?

Thanks,

Karen Robinette, long-term subbing for Kari Buness at Teeland Middle School