Pickup Vanish Logic/rule

[Pave]

I'm a bit confused how this is supposed to work:

Are the pickups in some sort of timer?

- The ammunition can be lying around for countless of minutes, while the orbs may vanish within two minutes. This could explain why some of the affinity-orbs I didn't pickup within two minutes vahished while I was still in the room (I just didn't keep watching to the direction of orbs due lots of hiding foot-soldiers I was busy taking down).

Is the a max pickup count avaible per "floor"/ground

- Do the pickups "teleport" forward when they aren't picked up earlier. Or do they simply vanish? There was a case where I left few Energy-orbs behind and on the next room I used more than 100-units. I got almost the identical amount from enemy drops and did some backtracking (which was the previous room). All the ammo pickups were still there, but the orbs were gone (these were enemy-dropped pickups, to clarify).

Maybe these observations could help up with the pickup system in future.

[Pave]

This still needs some clarification, because I can always return to pick-up some Health orbs after 15-minutes of baacktracking, but not Energy Orbs after 20-seconds...