Hearing a pop and then a pull left

Mine does the same thing. I believe it's either the slack adjuster or the brake chamber. My right front was doing it, but since I replaced it, it hasn't done it since. Only now my left one is doing it occasionally.

 

If the spring pin and bushing in the front of the steer axle spring is slopping around it can cause some stuff like that. Would not expect to see that on a truck as new as yours.
Never saw this on a steer axle but it could happen just the same and I will list several possibilities. Some are related to people that do not replace and or lubricate hardware. I like anti seize on all roller to shoe and spider locations.
The basic idea is that all the parts must be free to move. Some designs have sold anchor pins and anti seize between shoe and pin. On others the pins rotate in the spider. They should have anti seize between spider bushing and pin. One of the problems that can result from that is that the roller slides instead of rolling on the S cam. In time this causes a flat spot on the roller that wears the s-cam as well. As the lining wears faster than the steel components resistance between roller and cam stop travel as much as pressure on the lining. Then when more pressure is applied it jumps over the point of resistance pops and bang, high brake application. I had more of a problem with the brakes not wanting to release after this.
I even had this problem on a truck with the original brake shoes but it was a chemical hauler. Many kits in recent years have groves machined in the rollers to help them turn on the cam. I do not know if this is your problem but if it has shields remove one or both of them if possible. Use a spray lubricant on the rollers and if the problem goes away that's probably it.