4 piece set bonus and talent avalanche seems to be bugged. Sometimes they dont work with with rime and km procs.
Rime avalanche bug happens rarely about 1/10 but KM proc bug happens very frequently.
As far as im aware they dont have internal cd and they can happen with random rare procs aswell from my testing, so that is not the issue.
Also there seems to be death grip bug aswell, it is very noticable when doing pvp, it goes on cd without gripping anybody when there is no reason such as target being rooted or immune.
Please check these bugs they are actually pretty big deal for both pvp and pve thanks.