Teacher responses disappearing

I assigned a test and then closed it. I wrote up responses and sent. Some of my students logged in as a guest and some went through Google classroom. Now, some of my students can see my responses and some can’t. On top of that, some students responses have disappeared. I am at a loss. I have reopened the assignment, watched videos, and researched online but found no solution.Please help!

Hi there,

Could you message me the URL of the formative?