AsNoriuanswered grow question 2 years ago such shit with added leaf droopiness was confusing me most.
Without million of talks -
check ph and meter what how you measure, looks like ph imbalance caused restricted uptake of nutrition, calcium most in my eyes.
if this is not the case, i would put her on water and calmag diet for 3 cycles wet/dry/wet/dry, it should take you 10-15 days, she should perk up, if she looks happy after two even, return to light feed schedule.
Such symptoms on such nice big plant - only ph i would say. others could be not so sensitive and with such quick change of colour and damage ..
my thoughts ..
Happy Growing !!!