You can use the "Re-Calculate Grades" button to force the system to update grades. The best practice is to click "Re-Calculate Grades" anytime you add or edit a review, provide a teacher review, or do anything having to do with grades. For example, if you add a teacher review to a student submission (depending on your assignment settings) this could affect one or more students' grades, so you'll want to recalculate grades.
If you have done a manual "Override" of a student grade or portion of a student grade, the "Override" will be maintained even if you push "Re-Calculate Grades". The only way to change an overridden grade is to manually override it again.
In addition to the functions listed above, this button will also push the current grades to the LMS grade book after they have been re-calculated. If you've made any changes to a Peerceptiv assignment's grades within your LMS grade book and push grades from the Peerceptiv system again, the grades pushed from the Peerceptiv system will overwrite any grades in the LMS grade book.