Strong boxes don't spawn all enemies when on certain maps

Noted the following maps:
Titans Grotto
Path of mourning

Issue:
In two cases with limited space and strong boxes spawning more than 7 packs, all enemies were killed but the box continued to spawn traps/hazards and no items were ever dispensed.

Note:
While it is possible that they simply didn't spawn or the box didn't trigger as finished once the final enemies were killed, it would seem that since there is close by elevation changes in the map what may be possible is that the units were spawn WAY off screen on a lower elevation.