Name says it all. I feel like when I'm patrolling around (several times in Titan just now), after picking up a bunch of resources and/or chests, and occasionally after fast travelling, I just stop getting loot from said chests. If it's a glitch it'd be great for Bungie to confirm and let us know they are working on it. If its not and there really is a timer, it'd be great for Bungie to confirm and then stop doing that. Wasting a gamer's time by feeding them empty loot caches is a pretty shady move in my book. There's other ways to slow down character progression if you're so hellbent on doing so.