When you see something other than the Gradebook appear it may be due to the teacher not actually being set as a Teacher under their employment. To check go to:
  1. Core > People Finder > Select the Access Tab to land on
  2. Search for the teacher and click on their name
  3. In the Access Tab, click the Employment Button
  4. Edit into the Employment
  5. Under Employee Roles make sure Teacher is checked along with the School Levels. 
  6. Click Save & Exit
They should be able to log in and navigate to their class and access the Gradebook from here on.