I'm at Mission 71 where you need the 3 Lv 12 Attack % on main stats on attack heroes. I tried putting on level 12 Attack gear on my second hero and the completion meter went from 1 to 0 while I still had the first hero equipped with this gear. I spent at least 500k silver to get these Level 12 gears for this mission, so I am kind of concerned about this. I think I'm doing it right.

Any word on this?