Unfortunately, I won't be of any help but just wanted to mention that both plants that this has happened to me, have resulted in the same airy type buds as you have developing and they stayed that way.
I'm wondering if this has to do with excessive phosphorus as I remember reading that it can cause such airy bud. Though I'm not sure if the leaf curl and airy buds are symptoms of excessive P or they are completely separate issues.
If you look at this link in my diary, you can see the difference in the more dense plants versus the real airy one that has the leaves curling down like yours
It's almost as if the curl is a direct result of the bud not filling in correctly thus resulting in the leaves not being sustained by the bud causing them to droop or curl. But this is purely a hypothesis though