If you run too far or skip areas in Nightfalls you can make champions despawn. If you make champions despawn it counts as not killing them and therefore you cannot get platinum. If you dont get platinum you do not get ANY nightfall rewards. No weapon, no cores, no prisms, no shards, NOTHING.
PLEASE STOP!!!!!
We are not playing these Nightfalls for the end of strike chest for 3 legendary shards. We are doing them for the WEAPONS.