Yeah I know, that's why I'm confused and moved to the CV, but if rusty has had the same issue maybe he is talking inside the hub itself not just the locking hub.
I pulled apart my hubs once they were off and couldn't pick the problem. My trusted mechanic(who would never screw me over) also stripped them down and noticed that the shims and locking ring were buggered. even when reshimmed they didn't feel 100% satisfactory in there grip. I just replaced them both with new units and they are fine.
I honestly can't help you apart from that. His cvs might be pulling to far out of the hub when on full droop and not letting the ring engage properly. Who knows really. Lol