So either of the morphs has a 2 phases 1 is if you are over 7m from the target it "pounces" on the target and when you are within the 7m it puts a dot Feral/brutal carnage.
So attempting to use the skill on a big target boss like Telaria or any of the sunspire dragons it keeps "pouncing" even if you are 1m from the target.
Basically it's the old zaan's bug where the target's hit box was too far for set to proc it's back again with the WW skill.
Biggest issue is that the dot from that skill is insane, so missing it is huge hit for the WW in certain content