Anyone else have this issue? Last week it was feather #4 - it just wasn't there. #5 was, the one under the waterfall in the boss room. This week I grabbed the first 4 and now #5 is a no show. I'm just trying to get the light seeker triumph done and so far I can't. Both times I ran through the mission again to see if the last feather would appear. Both times it did not.