Hi there, I had exactly the same issue! I achieved an A in my PROD 2 coursework as well, however, I was also really shocked to see I had got 50 UMS (Just in a D Grade) in my PROD 1 paper, averaging my overall grade out to a C!!
My DT teacher is having the paper moderated and I am also requesting to see my paper!
Glad to know someone has the same issue as we were starting to worry...