That sounds pretty frustrating. I wonder if it wouldn't be a good approach to, say:

1. Make the exam the only thing that determines the grade (or technically, proves that the student learned enough);

2. Give out test assignments students can do, but don't have to;

3. Offer students for the professor to grade their work if they want to get some feedback on how they're doing.

Would that lead to less time wasted by tutors grading AI generated answers? From where I stand, students should be allowed to prepare for exams any way they like, with or without their professor's help. If they managed to learn, they pass.

When I was in engineering school ~20 years ago, some lecturers openly said that they gave the assignments just enough credit to be worth doing. Something like 10-15% of your final grade would be from assignments, the rest from the exam. So we didn't blow off the assignments to go drinking.

Of course, this a lot easier for some subjects than others. Subjects like Film Studies relied on exams much less, and assignments much more.