Maim: Immunity & Duration

Hey folks,

Im playing the Assassin Ascendancy-class and was wondering 2 things about MAIM:

--> How long does the movement-debuff MAIM last on an enemy?

--> Are there any Bosses or other monsters that are immun to MAIM?

The Immunity seems to be pretty important since it helps to guess how valuable MAIM is. If for eyample Bosses are usually immun to it and I try to max out Boss-DPS then its wasted to try utilize MAIM.

Wiki and Forum search didnt help here so I hope for you :)!

Thx in advance!