Looks like we’re going through the exact same thing. I was diligent with my LST early on which left me with a fairly even canopy to work with and this made it a little easier to manage. That said, the issue has persisted.
I’m also using a 2 part nutrient with a PK booster (Green Planet Duel Fuel + Massive bloom). I kept the bloom the same but gradually decreased the base nutes to 1/2 and now 1/3 (0.8-0.9 ec).
Also reduced the lights to 75% power.
In my case she’s reached the ripening stage, so not paying much attention to the leaves anymore (despite top leaves starting to show signs).
I suggest you also reduce your base nutes slightly but maintain the PK booster (without increasing to make up the ec) and see how she reacts. In my case, I found the leaf situation didn’t improve but the buds kept developing so I went along with it. Good luck and let us know how you go