well since no one answered, and i have no experience i went to my ask Ed book...Ed says that genetic weakness can occur over a span of time when one is crossing or breeding genetics...clones are the exact replica of their mother and have no genetic weakness but are identical to the mother...so if you're mother doesn't have the problem then its probably something wrong with nutes, ph, etc...its also possible your plants could have picked up a disease during cloning which has now polluted the line with an underlying disease...just did a lil research but i honestly have no expeience with cloning...i'm one of the few who like the variety given within a particular pack of F-1's because each plant has its own unique qualities...i like variety in my smoke