What is wrong with this Plant ?

I think you got bugs... It's interesting to see everyone else's opinion.. But why I lean towards bugs its just it looks like an overall/stress damage thing.. New and old leaves.. Even the patchiness of the leaves to me says something is snacking on your stuff and it's not a growth problem... They don't like they've been neglected and I'm sorry if this is indeed the case...

Thrips!! My guess is you have an infestation of Thrips. I brought them inside from my outdoor grow in the Fall and completely destroyed one of my near harvest plants. I thought I was under watering and the leaves were all drying up and getting crispy. But it wasn’t watering issues after all. I used my jewelers loupe to check buds in my other tent and all of a sudden, I saw a thrip walking on my buds. I quickly looked at my troubled plant and discovered that was the case. They even infected my new batch that was growing on my shelf T5 setup. The telltale sign is the white spots on the fan leaves. I bet if you look real close even without a magnifier, you will see tiny bug movement. You can treat them easily in veg, but it’s more difficult in flower. I used a spinosad treatment on my young plants and they recovered fine. Do you see any tiny bugs flying around by your light? Thrips eventually are able to fly and you’ll see them buzzing around your light. Look up thrips and treatment during flower. Sorry to see this happen! I had to learn the hard way and I will now take precautions if I’m growing outdoors again. Good luck!

Looks like you have an iron deficiency you can from the lime green or "pale" leaves. Iron deficiencies are often caused by overly high ph and can be corrected by flushing your medium with clean ph’d water and if necessary, adding an iron supplement.

Get a loupe or microscope and check under your leaves. I see possible signs of mite damage on the leaves surrounding the wilted growth. The wilting and twisting can be cause by mites injecting a toxin in the plant when they suck out the sap. broadmites but will usually also have a bronzing affecting on the leaves as well. You can see spidermites with the naked eye but you will need magnification to see broadmites.

Hello friend, I feel like there are a few possibilities.... but if you don't see any bug activity, and your plants aren't getting light burn...I think i would go through and possibly check the ph, if you use a pen maybe test some water and then recalibrate the pen and check the water again for accurate ph. I think ph because of the stripping on some of the leaves and also the tips look like they're beyond a typical nutrient burn. I had a series of plants that had insanely messed up leaves and i couldnt solve all the various symptoms for so many deficiencies etc....until i checked my ph pen and found i was watering at like an 8 ph. I hope you can find your solution. Happy growing. ✌️