VPD out of range can cause significant issues.
This YT video might provide insight.
One key issue is that as transpiration increases, water uptake increases and, in turn, the amount of nutrients in the plant increases and that can lead to nutrient imbalances. The plant will keep the same % of water, over time (it has to or it would burst), the primary mechanism being by opening the stomata and allowing the water to escape. That helps cool that plant.
But what happens to the chemicals that came in with the water? If it can't use them quickly enough, that will tend to create an imbalance. Perhaps that's what happened here?