I missed several rewards drops and it seems problem may be related to the fact they tried to land on natural roof, but outside of the room. At least the screen is centered at such point.
It seems it may be also related to this (https://ludeon.com/forums/index.php?topic=51383.0) bug, though this one seems being fixed, but behaviour is very similar.
My mistake, seems i expected reward pods while it was notification for the mercenaries pods.