Small leafy buds

Few possibilities. Might be over stressing with the training. This could stunt her early growth so you don't have much of a plant when it goes into flower. Certain strains can handle a lot of training, but others don't respond well so something that has worked in the past may not work with different genetics. Lights could be too weak. You've had other successful grows, so this may not be the case. Could also be a malfunctioning light not doing its job. Too much N in flower. This would explain the extra foliage and airy buds. The plant in your picture looks like you have it ready for harvesting, but if this was some extreme defoliation technique like schwazzing, then it's possible you're doing it too soon. You shouldn't do it until after the stretch. I believe about a week after but I'm not 100% with the timing. It looks like your plant never stretched so... Hard to say off of what you posted, but these seem like the most likely scenarios to me. Hope this helps.