Drooping top leaves

So this could be a hydration issue?

Your environment sounds good so I reckon a tiny bit under watered - water isnt instantly absorbed by roots like a sponge, it takes time. Always water slowly too, though. Don't dash it in like you are throwing a drink at someone you hate, give them some love haha Slower watering allows you to saturate the medium without it all flushing out of the pot. With slow watering you may well find that the same amount of liquid will not run out of the pot but it will all be absorbed in the soil, also, very dry soil goes hydrophobic so watering slow is key. Water dry soil too fast and the water will just find the path of least resistance and flow down and out of the pot without really getting sucked into the soil.

The room temperature is 26 degrees Celsius and the leaf temperature is 24.5 degrees Celsius. I always wait for the pot to lighten before watering. The pot becomes lighter, the leaves droop and I water it, but then the leaves hang more. Soil Ph 6.5. Humidity 55%. The thing that bothers me is that instead of watering slowly, I prefer to drain the water quickly into the pot, maybe this is beating the roots.

Yeah that is odd - how often are you watering and what do they look the day after watering? It could be that you are letting them get toooo dry before watering and they arent absorbing quickly enough after a watering but are continuing to wilt a bit and be slightly underwatered but watered and corrected just in time. If they look good 12-24hrs after watering I would say water a little bit more frequently. Don't let the whole pot get bone dry but dont over water either - a hard balance! Haha Try weighing the pot when the plant is happy, weighing again when it droops, weigh again after watering and then again when plant is happy - you will then see how quickly it is going through the water you are giving so you don't let it dry too far before watering again. If for example the pot weighs 4kg after watering and 3.5kg 24hrs later when the plant is happy and 3kg when it looks sad again you can approximate the amount of water per 24hrs and water back up to 4kg when it weighs say 3.25kg so you avoid under and over watering - a couple of days attention and some basic maths would see you good in that scenario. Thats my take on it - my current grow the big plant did the same early on cause I was afraid to overwater then I used the 'weigh the pot' system above and based future waterings on a 2 day wet/dry cycle and it has served me very well. The plant is question is now close to harvest and has dropped from like 1.25L/day down to about 500ml a day in the space of about 10 days. Long answer but I hope that helps.

Hi—- environment! Too much water? Too little? Lights too close? Too much heat, humidity?

Ur light isn't overly strong but what light schedule has it bn on bro? What changes have you made and see if we can find the problem between those stages 👍