Any ideas of what issue(s) this is

died leaf burned leaf befor nutriens sock this hapend after burning.

I’ve got a similar issue, not as bad but same cultiva from 00 seeds week 8 flower, my tips have done the same and pointing down so I’m guessing it’s to much light, I’ve dimmed it a bit and checked my run offs I’ll let you know if I have any luck

thats burn, not lack. maybe heavy flush disolved all salt build up, but was not enough to take it out of medium and she burned take off that all branch, paper tape mask to cover wound and finish rest. very potential to mold issues. happy harvesting !

Dude you chasing a ghost, your plants are going through natural faid, I know most people see some color change and automatically think deficiency but not this late in the game, they're budding good and they're sucking up.extra nutrients from the leaves, make sure your VPD is on point and keep doing what you're doing..

Burning from a toxic build up of nutrient salts in the substrate, probably caused by failing to ensure proper/adequate run off when you irrigate. Nothing you do now will "fix" it before harvest time.......or even ever at all.

Next possible reason may can be - burn from fan. I saw it at a friend's grow, he had a strong fan and it killed plant week before harvest. You can easily find it on google, wind burn

There huge lock out in roots there finished any way just fully flush your plants with clean water they finish 👌

What are you feeding the plant? If it’s dry, you have too much light and too many nutriens in the solution, the respiration of the plant sucks the heavy nutrien solution up through the plnat and burns it. I would recomend flush the plant and only use minimal nutrition. If you need help calculating, i‘ll be glad to help.

Mobile nutrients manifest at the bottom. Immobile appear at the top. But you got some nutrient burn goin on there. I remember cooking branches that got too close to the light and they looked just like that. I'm sure thats not it cuz its a lower branch, but definitely nutrient burn