There’s a cool down for looting chests. If you do too many too fast, you just get nothing. It’s a real problem on the smaller worlds. It affects Cayde’s chests, too. I got nothing from the last two chests on the first week because of it before it was a widely known issue.

The mentioned "farming timer". The gist is that certain chests (Including Cayde's chests) count in some system that limits how much you receive/can farm. Opening two chests or Planetary Materials in rapid succession (about 15 seconds) will often have the Rep Token or material not spawn. I haven't tested exact numbers. But eventually you stop even getting glimmer. Some chests count toward the total but reliably spawn items (I believe HVT chests are this) while others are completely separate (Public Events, Regional chests) and I haven't noticed any real impact.

It means you can't just do straight farming, but it is a soft limit and has no UI elements. I would rather a) only have chests/materials spawn that I can pick up b) have a UI/interface limit with a timer wherein I cannot open new chests/materials so I am not wasting them.