Is this nite burn or heat damage please help

Hi guys i have started having a prob with the suger leaves on my buds are turning brown a lot of leaves yellowing week 7 nearly 8 first time monster cropping pineapple haze has grown perfectly since the beginning no probs and last 2 days bam this shit starts now I think it's maybe nute burn or heat but my heat hasn't changed at all and still feeding the exact same since the start of flower here are some pics

What medium do you use? If it's hydro then if you've been feeding the same you may be due a flush (leech), water with a weaker nutrient. Either way towards the end you wanna back off the nutes.

It's normal soil temp 25 degrees Celsius. Humidity 50% pH 6.6 all same