I have one out of three doing this, so I'm kinda dumbfounded. I know I've had some pH issues and I suspected over Nitrification, but after 3 flushes, it still exists. I've tried many lines of thinking and can only come to two possibilites. Even though drainage didn't seem to be an issue, I just found that this pot did not have the extra drainage hole I put into the others. I kept adding dirt to the top off the pot, which was some cheap heavy soil that also had a lot of peat. Even though I don't believe she is root bound, the top of soil seems to retain moisture and is spongy after watering. I know she isn't drinking as much as she used to, and may be finishing early for me. This plant had this issue for a long time now, and after reduced feeding, flushes and extra drying time, she is still doing this. She hasn't had any miraclous recovery but seemed to improved slightly. Shes' still going to produce some major buddage for a very stressed girl. I can rule out too much N and I feel there is either an issue in the root zone (which I will inspect after harvest), or like another poster suggested, genetics. After wracking my brain continuously on this matter, I'm almost glad to accept the fact that maybe, just maybe, it wasn't me.
Water intake issue or genetics is where I'm hanging my hat for now. In the following pic some leaves have been trimmed or removed. Sugar leaves are spotting and turning up and dying off. The claw became more pronounced after this flush on a few leaves. My other plants leaves are flat or pointing up, not down like these.