Enrage +5% damage debuff not working for me in SG

[Samsgaard]

Over the weekend, on multiple runs in the featured instance (SG), I could not get this debuff to land on the bosses. Seemed to defeat the purpose of switching to yellow line for those fights. No problems outside the instance - the bright yellow face reliably shows up on any mob's buff bar, and I can get it to stack using Trickster.

Any ideas on what's wrong?

[Oelle]

back in the days of lvl65, that skill had a different effect. if i remember it right, it made enemies attack each other or something like that.
the effect got changed, but the immunity of mobs that should not fight each other did not change.
therefore, lots of enemies in older instances are just immune towards enrage.

[Samsgaard]

I vaguely remember it as inducing random aggro. Don't remember it causing mobs to attack other mobs, but maybe!

Anyway, immunity in "older" bosses would explain the problem. Thanks.

[dwarfThar]

It induced random aggro and increased incoming ranged damage. There was also a trait that enhanced it to force ranged foes into melee if I remember correctly.
The enemies-attacking-eachother trick was a new thing with mounted combat.