Hi western ,
That is weird, They look healthy -
ive never used Fluoro for flower - only for veg - i use a High Pressure sodium for flowering - and after 3-4 weeks at 12/12 you should have buds well started already..
think maybe Burwoodkush is on to something - maybe there has been light leaking in during dark - and the plant doesnt know if its veging or flowering.
Good luck..