What is going on with this plant?

Light/heat stress raises your light higher or lowers the power of the light will lower heat also. see the new leaves and how are curling up, The sign also checks your humidity can be the reason. But you say is only on this plant then this could be the light DLI hit stronger there 🍻

I grew that strain in all possible conditions. Hate RQS, but its great strain, was taking any pain. Something heavily wrong with feeding. Looking at diary and amounts, plus bleaching .... think you firstly - overfed, secondly - your pots are overwatered. Maybe light too intence to add to all. I did grows in soil with 0 nutes, you bombard such small already ... Sort those two, raise lights and all should go way better. Good luck !

yellowing from inside out on new growth... looks like Low S, but it's quite early on. If in soil, should have a starter charge, i'd guess. Stop starting with "i did everythign the same so it can't be the environment" because that type of thinking will only get you in trouble later. fact is numerous things are different that you cannot see or don't notice. could be a weird batch of soil.. may have had an unusual amount of amendments in that pot etc.. could be a picky plant.. could be a slightly off balanced nutrient ratio that doesn't work for as many plants as a better one would.. etc etc.. a plethora of moving parts invovled... pH could be different which potentially requires a different ratio of nutes for everythign to be plant available and sufficiently in supply.

Your soil looks like it needs a good soaking. If you haven't had any runoff at all then your soil is to hot, the roots will hit dry patches and not like it. Water all the soil until runoff, wait for top inch to dry before watering again.