I have tried to import grades from Google Classroom to the spreadsheet grade book. I have tried multiple times and for some reason the grade book is showing 3 columns of the same single assignment. Same grades, etc. I have checked the classroom and I only have one of these assignments of course. I'm not sure how to proceed. See image.
EDIT: And now it shows 4 times as I have tried to import the grades again. Usually things are overwritten. This week is the end of semester...terrible timing ;)

Thanks for the reply. I unfortunately don't have the time to create a non-terms grade book as I am entering my final marks. I was able to delete the multiple columns and import only one instance of the assignment. I feel as though if I do another import it will double up again for whatever reason. Also to note, the [[ungraded]] feature was not working with this assignment for some reason. Thank you.
I see that you are using the terms type GradeBook which is currently in beta testing. However it should not be importing multiple times, I have submitted a bug request. Is it possible for you to create a non-terms standard type GradeBook for each term and average out the marks? Since everything is in Google Classroom everything will import again (except for weighting). You can set import dates here:
https://docs.google.com/document/d/13YSVoxR-KVG0aJKjUcyeps3xfLPfDdi5JoPb0aC1dfk/edit#heading=h.9bd7a0mglr4o