But I did received duplicates on characters I was still missing armor for and did not get all items because of it! What are your criterias? There are also people who got 2 Jubilant Engrams on a character they already had everything, while they missing 3 armor pieces on another character. So apparently your fix does not work properly.

Is there any sort of list or explanation of what those criteria were?

I did not receive anything either. I had everything but some armor pieces, and I got much more than enough of the jubilant engrams to cover the remaining armor pieces I needed.