Your course is integrated with your institution's Learning Management System (e.g., Blackboard, Canvas, etc). If you see a red exclamation point next to one of your scores in My Scores, then Perusall was unable to sync that score back to your LMS, so you won't see it in your LMS gradebook.
To get Perusall to sync the score back to your LMS, launch the Perusall assignment from the corresponding assignment-specific link within the LMS (a link or assignment in the LMS that has the same name as the Perusall assignment). Once you do this, the red exclamation point should disappear, and you should see the score show up in your LMS gradebook within a few hours.
Going forward, make sure you launch each Perusall assignment from the corresponding assignment-specific link in your LMS.