Why does liquid on top non overlapped leaves appears?

Daytime rh of 50 will easily spike to 70 + if there is not adequate air controls. I dont know how you have your tent setup but dropping temps even 10f at night will easily bump rh up 15-30%. The air holds alot less moisture when it's colder. This easily makes a 50 a 70 overnight. Along with the fact as the plant gets bigger the more water it will pump into the air at night. This is a by-product of cellular transpiration. Nighttime opposite of photosynthesis. We spend so much time focusing on daytime we often overlook and spend little time caring about night environment when it's almost equally important. Good

A primary component in photosynthesis and respiration Responsible for turgor pressure in cells (Like the air in an inflated balloon, water is responsible for the fullness and firmness of plant tissue. Turgor is needed to maintain cell shape and ensure cell growth.) A solvent for minerals and carbohydrates moving through the plant Responsible for cooling leaves as it evaporates from leaf tissue during transpiration A regulator of stomatal opening and closing, thus controlling transpiration and, to some degree, photosynthesis The source of pressure to move roots through the soil The medium in which most biochemical reactions take place Relative humidity is the ratio of water vapor in the air to the amount of water the air could hold at the current temperature and pressure. Warm air can hold more water vapor than cold air. Relative humidity (RH) is expressed by the following equation: RH = water in air ÷ water air could hold (at constant temperature and pressure) The relative humidity is given as a percent. For example, if a pound of air at 75°F could hold 4 grams of water vapor, and there are only 3 grams of water in the air, then the relative humidity (RH) is: 3 ÷ 4 = 0.75 = 75% Water vapor moves from an area of high relative humidity to one of low relative humidity. The greater the difference in humidity, the faster water moves. This factor is important because the rate of water movement directly affects a plant's transpiration rate. The relative humidity in the air spaces between leaf cells approaches 100 percent. When a stoma opens, water vapor inside the leaf rushes out into the surrounding air and a bubble of high humidity forms around the stoma. By saturating this small area of air, the bubble reduces the difference in relative humidity between the air spaces within the leaf and the air adjacent to the leaf. As a result, transpiration slows down. If the wind blows the humidity bubble away, however, transpiration increases. Thus, transpiration usually is at its peak on hot, dry, windy days. On the other hand, transpiration generally is quite slow when temperatures are cool, humidity is high. Hope that helps.

Look up VPD (vapor pressure deficit) You know how humans sweat right? Well imagine you're in a sauna or steam room, ect. Fans and ventilation, ect will all impact how much you sweat and such. The same thing happens in plants. They want a good condition to live in. Imagine being sweaty all damn day sweating 24/7. It's a no go. You also have dew points and such (thats for outdoors). Anyways, as the other stated when your plant sleeps, or when your plant needs water or was over watered, the leaves will drop/droop and then your plant breathes. Be mindful in late flower, as you may want to defoliate and not worry about any issues.

When the plant sleeps the leaves will droop down a bit which can cause them to touch each other causing wet spots, then when they start waking up the leaves start moving up to there normal position to catch the light.