Wow i have never heard of this.... Stems so dry they are snapping in flower?

I have a strict watering schedule, growing in rockwool. PH 6.0, general hydroponic 3 part nutes. It has been 9.5 weeks in flower and I trimmed today, stalks are literally snaping and the buds feel a lot dryer then they should.....wtf?

idk man got me
maybe it is a auto harvest strain