From the patch notes:
Throw Mine and Mine Field skills: Certain friendly NPCs no longer detonate mines.
Scatter Mines skill: Recharge is no longer impacted by the Rifled Barrels trait.
These present new issues with mines that are greater than the original issues.
Mine Field no longer explode when enemies cross them and can only be detonated manually. Furthermore, when the Rifled Barrels trait is active, the mines not only no longer explode, but they trigger a 20 second cooldown on Mine Field whenever any creature (ally, enemy or yourself) steps on them (regardless of Recharge Rate reduction from the Tools line). This cooldown resets whenever any creature crosses them (thus making them unable to be even manually detonated) in a perpetual loop.
