So I was one of the guys that got the Zekvir curio very early which caused a bug to not drop any curios. This was apparently fixed but I am doing a lot of delves T11 now and none of the curios are dropping. I only have 5 rank 4 curios when I look at the achievement (Branntastic), and according to WoWhead 33% of the people have this achievement. Since I play a lot something clearly seems to be broken to me.
How do I get these curios dropping?