I setup the Expense Report case type assignment as per the instructions in the sefl study guide. The cases when created should be assigned to 'Manager' instead they are getting assigned to 'administrator@tgb'. I verified the assignments as well. There seems to be some basic setup issue in the org.
Please clarify if you are encountering this in System Architect Essentials 7.2 course or Senior System Architect course. If System Architect Essentials, there is a known bug regarding routing. It will work temporarily and then revert back to "current operator". THe earlier exercises in the course related to Expense Report are for practice purposes only. The only workaround you have in this version of the exercise system is to either ignore routing being buggy, or redo routing at end of each exercise. This is only an issue in the first few exercises. After you begin building out the Onboarding solution, you should be fine.