Terp1answered grow question 3y ago Permanent poor and fluctuating environmental conditions bring such a picture to light. Your VPD is way too high... we already clarified that. Your plant is burning because it can't transpire quickly enough, as would be necessary with such a high VPD. This causes nutrient salts to accumulate in the leaves and they burn.
Unfortunately, you need to find a way to lower the temperature in the tent (different room, less light, hang the light higher, stronger exhaust, open window... for example) and also increase your humidity (humidifier, spray the inside of the tent walls with water, for example).
Check out VPD tables online and get the sensors that allow you to monitor temperature and humidity, preferably ones that also show you the current VPD.
VPD - Seedling - 0.6 kPa
VPD - Veg - 0.8 to 1 kPa
VPD - Bloom - 1.2 to 1.5 kPa