a rare plant is pickier than others... not all formulas are as well-balanced as others... sometimes you simply cannot feed them all the same way, but i've done 7 strain runs before with no problems and rarely have to adjust much beyond how environment impacts rate of uptake in roots. I figure 90% or more of the plants i've grown were fine with my standard mix, so a well balanced feed can work on most plants. (120-some plants? still a small sample)
if it looked retarded fro get-go (ignoring early blemishes on first few nodes), figure it's something wrong with how it metabolizes things... those plants typically never get right. One of my NL was wrinkly and never quite right, but it was fucked up from sprout.. easy to say genetics there. plant diabetes or something, lol...
late in flower you also have senescence... so, on top of what has been going wrong, it goes down hill more easily at this stage... less of a push needed, so to speak. Really see the quality of your feed late in bloom. if it falls apart quickly/easily. that's the mix.
so many relativistic factors at play.. track what info you can, if you want to eliminate least likely possibilities.. otherwise, it's just stabbing in the dark unless lucky to run into a homerun.