People stage diving off of Caustic traps

[digiholicA54]

When playing with Caustic, what is the time limit or range for a trap to actually trigger.  This season it seems like often if a trap is thrown and an enemy is within a certain radius that the trap will not trigger unless they move out and back in.  This leads to enemies practically stage diving off of traps without triggering them.  Couple that with about 1 in 4 traps not actually expanding when thrown, it makes him a tricky character to use.