Inconsistency in grading

If you have the same problem as me, you may have experienced inconsistency in the grading of different exercises of coding assignments, this is due to the auto-grader so if you are experiencing this after you made sure that the last exercise of your assignment is correct rerun the data loader and this time pass the grading part of the last exercise and run the auto-grader of next exercise hopefully it’ll fix the problem.
I am really curious to know why this happens in assignments so if anyone knows why please tell me. thanks

Thanks for your suggestion.