When viewing student grades in TAC, please keep in mind that when you enter the TAC environment, the SEM tab and the ALL tab are selected by DEFAULT. So, when you select SCORE on the TAC home page, you will get a view of your students, all of their assignments to date, and student grades.
At the next screen, you will see a list of your students. Be aware of the SEM and ALL tabs, as well as the MP field. The grades reflected depend on which tab and field is selected.