Students completed exercise but I cannot see it

I have quite a few of my students (maybe 10 of the 160) that completed the Khan exercises that I assigned but when I pull up to view the class scores, those students scores are missing.  The have sent me screenshots of their work and it is complete, yet it looks incomplete on my end as a teacher.   They are all in my Google Classroom.  And that is how I set up my Khan Class Khan accounts, importing the Google class lists.

I would appreciate any help!  I was hoping to use Khan a lot with them during this Distance Learning.