Shaman Slows

[Netherzul]

Another thread, sorry but another question just hit me.

During live, my main was a Shaman and iirc, Shaman slows would land on boss targets, but the full slow wouldn't take effect. It would land for something like 25% or 30% but not the 75% of the final slow for Shamans.

Is this the case on p99 and during velious? Which bosses currently can it land on? It's been so long that I can hardly remember.

Thanks again