I was messing around tonight in the EDZ with my Revenant subclass, when I noticed the "Grenadier" bounty not updating properly on Glacier Grenade shatter damage kills -- something which immediately started working properly again the moment I replaced Whisper of Fissures with a different Stasis Fragment (I swapped Fragments after tossing out a Glacier Grenade with Whisper of Fissures equipped, and it still counted towards the bounty objective). I suspect Destiny 2 is classifying the extra damage dealt separately by this Fragment as not being from a grenade source, likely due to how it can also trigger from kills on frozen targets, and probably due to being counted as the last "hit" in those cases. However, this also means it's not possible to rely on the shatter range increase on Glacier Grenades from this Fragment for bounties requiring grenade kills.