I've noticed that the coffer sometimes deviates slightly away from the lane it's in. Though, I don't think there's anything wrong. I notice this occurring more frequently when the track becomes narrow. The lanes of the multiple courses are bent out of shape when the track becomes smaller. I think that's why it seems like the chest is in the same lane and it looks like you run through it, but you don't actually pick it up because you actually weren't in the same lane.

If otherwise, refer to Kerii's post.