I have this issue. I have all the fragments, yet the insight card hasn't popped. I think this is because it's glitched. A coding error that needs amendment as grimoire is account based, but for some reason only this card seems to be character based. I have all the fragments on one character but did one of the challenge modes on another. Making that character one fragment shy, even though technically I do have them all. This is likely why it hasn't registered even though it should. Maybe that's your problem too. Check and see if I'm right. I wish bungie would fix this though. It's a real problem.