Volatile Grenades/Cluster Bombs - Not reducing/increasing times

I tested this with all grenades.

Explosive, Oil, Gas, Volatic, and Flash.

I tried it with it active, and with it not specced. The detonation time remains the same.

Both passives do not appear to actually change the detonation time in the detailed information tab, could just be a visual glitch on the stats.

on PC, Witchhunter ascendancy.