All students kicked out of Course, Teacher is in People

Community Member

All students were kicked out of Course. I have an admin role and our institution has Canvas integrated with our SIS system. In our system students appear enrolled and they used to have access to the course on Canvas until it disappeared because they were kicked out. 

This happened once when the end date was wrong, and students were put back again when I changed the date in our SIS.  The dates are as they should in Course settings. 

Everything seems normal. How should I proceed?