My ds (now 12) was very much like your ds in 2nd grade, and we thought all those same things... he was giving up, he was a perfectionist, etc. And we were way off the mark in what we thought vs what was really going on with him. By the end of 2nd grade he become so extremely anxious about school that we took him for a neuropsych eval at the recommendation of our pediatrician, and we found out he had a previously undiagnosed disability which was really what was at the root of all the "giving up", daydreaming etc - he couldn't do the work, but we were knew him at home as the extremely intellectual being that he is - because when he was at home, no one was expecting him to write anything.
There may be a reason he's "refusing to move forward" - if it was me, I'd seriously consider getting a private veal. If it shows nothing - that's really really good - you can move forward knowing it really is just refusal to do the work. But if you discover there's more to it, you'll be very glad you found out now and you'll have an opportunity to get good input on how to move forward to help your ds.
Best wishes,
polarbear
