This is just a guess.......but did you feed them again after you flushed them? Have you fed them since? They're not hungry are they? They don't seem big or bushy enough to be really rootbound......they look like they've been sort of hanging by a thread for awhile. That's what makes me wonder about fresh nutes.......but again......strictly a guess. (and I make that guess based on the assumption that your ph meter is working correctly and you have indeed checked the ph on whatever is going in and whatever is coming out the bottom.)