Pls help

You are dealing with defo heat issues for sure. I know we been through this on our chats. To lower that you can get a cheap humidifier and it'll help them leafs take in fluids. But it might also be down to overwatering or underwatering mixed in with N tox. There's a few reasons your leafs can go like that. But with such heat your roots would be working hard so it's too much food and to low an RH. But been that I take it you flushed it and restarted but it doesn't seem to have fixed but only got worse, so your base is having to work overtime and too much N mixed with heat. Drop your grow and increase your bloom ratios. But if you can get that RH higher. So I would go with poor roots and problems with nutrient uptake (too much). A higher RH will take some strain of your roots and if you can get a root stim it wouldn't hurt. I see it's gotten worse from the last pics you sent me. So try and higher your RH if you can. Feed water more often but with less feeds. One base nutrient feed a wk is enough. And if you can even mix up and don't give the all the same nutrients at once. If your heat is that high then like me your soil will dry up very quickly so I find giving smaller feeds every day is working out better. Also, idk how often you have your fan blowing on your plant but I did c in the last pic the fan was beside a radiator and it was a static fan also. An 180degree fan is best so you don't have constant air on your plant. With such hot environment you'd be surprised at how fast a few damp towel will quickly raise the RH. Good luck buddy.