leaves going bad

You need to give them a good dose of calmag (Calcium & Magnesium) LED grows make the plant need more magnesium due to being exposed to a higher PPFD compared to HPS, it also means the plants experience lower leaf temperatures making them need extra calcium, the plant can’t move calcium from its lower leaves because it’s not a mobile nutrient. Check your nutrients and make sure they contain Calcium and Magnesium. Aim for a PH of 6.5

pH being a bit high shoudlnt cause this sort of damage. the damage is also more thna just the top leaves, so light isn't the cause of all of it. both of these things you want to get into a more ideal spot, but this is more likely a nutrient imbalance. often times marijuana companies instruct way too high of dose in flower. often way too much p or k. you say 6.2-6.5 and runoff is 1 pt higher? does tha tmean 6.3-6.6? that's no big deal.. but if you mean 7.2-7.5 that is too high. this is a sign of shitty nutrients that aren't ph-balanced. you are in a soilless substrate, so you need to get hydro/soilless nutes. these are 100% soluble and 100% chelated ready-to-use by plant nutes. they should also be ph-buffered to 6.0-ish. pH swing is a sign of subpar nutrients manufactured by some company without knowlege or expertise as these things are known and common practice with any professional Ag company. i don't see any bleached buds. but that would be a sign the lights are too close. there may be more than 1 thing going on here, so one things does not preclude another. soilless -- fertilize well-balanced mix at 1.3-1.5 EC with 10% runoff every time... the runoff avoids buildup, so when you do see symptoms you know it isn't due to watering habits. it can still be from a too-high mixture of fertilizer... observe and react. over time you dial it in and should have zero issues seed-to-harvest 95% of the time, in regard to nutes. feeding aplant should be easy and rarely something you have to worry about. it's simple and easy to do if you don't follow urban myths or buy from shoddy marijuana branded fertilizers that also tend to cost 10x more than they should while using ubiquitous, common ingredients.

Honestly, you must check the EC and pH levels of the soil, it’s the only way to determine what is the problem. Take a sample from the drain of the pots to control the pH and EC values of the soil. At this stage of the growth, reading the leaves symptoms is not accurate enough to fix problems.

Ah, it sounds like you might be dealing with light burn. This can often get mistaken for nutrient issues or pH imbalances, but if you notice the problem's mostly happening towards the top of your plant—right under the grow lights—that's a big clue. Plus, if you're seeing some mild bud-bleaching, it's another hint that your lights might be too intense or too close. Maybe try dialing back the light or moving the lamps a bit higher up. Hope this helps!

In veg 5.8-6.0 In flower 6.0-6.2 Those ranges you should follow. If your nute line dont change colour of water i would recomend aquarium drops. For soil i found small range 6.0-7.6 For cocovyou need a bit lower like 5.5-7.0 or something like that. Drops never lies, any meter if not cared or maintained start to show bullshit. I changed like 4 BlueLabs and 50 cheap yellows. Fall, shake, overdry probe, aka no kcl used or just dont use long and they go bust. I went to dry amendments and drops. Maybe more expensive option, but i always load right ph.

I grow in coco perlite I keep ph at 6.2 to 6.5 and run off is about 1point higher then what i put in and is only been in flower for about 21day still got about 3 weeks or so left

If its soil, its only not following right ph. 90% of mew growwrs have it at weeks 2-4 of flower. When pot gets totally poisoned and cant keep right one. Ph ph ph ph in soil is all that matters, then goes wet/dry regime, aka watering right when needed. I did a diaries recently with 3 plants, small for me 30 liters pot only and no nutes at all. 100g each. If you didnt overload mutes or underfed , its always ph or watering when you see such things.

From the looks of it, and the different signs it's showing. I would look into what the ph is of the growing substrate. It looks like it is in a lock out. Plus the bud does look close to done or done. I would check trichromes as well.

maybe it close to ripen and draw nute from those leaves ?

its only on the top few leaves