i agree, looks line nutrient issue to me with the reveg mate, everything seemed to be going ok,
or it could be that your over watering, remember it dont need anywhere near as much water as it did before harvest so if you do decide to flush then let it totally dry out before you do anything else to it,
it looked like it was going ok but as its going crispy that suggests their is some issue, ive not had any problems with doing a reveg, they dont need much nutes after harvest so just a very weak sollution then it can go 2 or 3 waterings before next time it needs nutrients,
so id spray the leaves with water to get some moisture back in them to stop them going crispy, then could it be that its over watered, they hold lots of moisture after harvest due to the plant using very little out of the soil as it dont have no leaves to use up the water, so the pot will possibly only need watering once every 10 to 14 days at this stage, just let the pot dry out before watering again, the roots will be low down in the pot so it could be root rot so let it dry out as the plant wont be using nearly anywhere near as much water as it did at harvest, its not a loss yet, it will still recover and still be a monster cropped plant, if you have fed nutrients then id possible flush until you have run off and then just put the plant to one side and forget about it, everything was going ok until a few days back so if its only nutrients youve gave it then thats the problem
so either flush or if you just think its down to over watering then raise the pot off the ground so air can get to the drain holes so it dries out quicker and just leave it to do its thing, it will recover, so at a rough guess id have to say its either badly over watered, you can check when it needs water as you just poke your fingers down the pot and pull them out, if soil sticks then dont water but if its dusty and dry then water, its just a big pot holds a lot of moisture and a small plant will be using very little as it just dont need it,
if its not over watered and you have let the pot dry out between waterings then it could be to much nutrients, when you fed nutrients did you go back down to the veg 1 feed or seedling feed schedule as this is where you need to start again, you need to start with the very first feed schedule and only at 1/2 the stated dose, they dont need much at this stage of growth,
so over watering or to much nutrients, thats what id guesss at this stage