I had the same issue and posted it here some months ago, Aron saw the post told me to call him.
Here is what he told me personally:
Some aren't used to the Kifaru waist belt support. It can take a getting used to.
I told him when I raised the waist belt up all the pain went away. He said some guys have to do this, just remember to adjust the shoulder straps lower to accommodate this higher than normal position.
After seeing the pic above in this thread with the guy and the Tahr, I realized I was simply trying to run the waist belt too low. I was only off an inch, maybe two, but it was enough to pinch the hip.
Now I run the belt just slightly higher than the naval rather than thru its middle, and I am good to go. The belt is still getting support from the hip and keeping the majority of the weight off the shoulders.
When I am a few miles in , the hips sometimes hurt, I simply need to recinch the belt (same as a horse saddle) and the pain goes away.