Question - Extended Target causing no assist

[sgamer75]

So I have been having an issue and I'm trying to figure out what the deal is.
My puller acts like the tank is not engaged many times, this includes pulling a second mob just after he pulled one to camp, and not assisting on single mobs sometimes.

This only happens on my main/puller/monk toon.
I did add to extended target window: Main assist target at the top, this lets me target the main assist in other groups raids, or even in my own group with a single click.

Could that be causing my problem?
I tried changing INI's with no luck.

 

[ctaylor22]

Make sure you start your puller with your tank targeted and/or your tank is set as the main assist to the puller. Make sure your Tank is main assist and is not assisting the puller.