Need Help with a10s

Not sure if this is in the right place, but could really use some help

My group is working on a10s and we're having problems with the adds

https://www.youtube.com/watch?v=_mXdZvo70KE

skip the around 9:20 when the adds drop

We made it to enrage once, but the last few runs the adds just aren't dying to lb3 anymore and we can't figure out why

from the looks of things they're under the affect of the vuln up when the lb3 hits, which should kill them, but they're still surviving

Ignoring the little issue with aggro at the start of that phase, we could use some advice on how to better position/kill the adds

any advice helps, thanks in advance!

You need to make those adds got defense debuff from dropping balls first before lb3

^What the sexy man said. You need to use the ball trap and let the adds get hit by it before LBing.

As Paladin, I always hit the adds TWO times with that ball just for good measure (Hallowed Ground makes that situation very easy.) Sometimes they aren't positioned right on the first hit, or two flashes wasn't enough initial aggro due to critical hit healing. There's tons of time to work with, and I'm not sure but I could swear those adds rebuff themselves if you take too long. Hitting them twice with that ball always gets the job done. Just make sure you caster LB3 as soon as the "stop attacking / moving" mechanic is finished.

Also make sure the big add don't buff the two others again before the LB3 hit them. We usually have our brd silence it to be sure.