The whole issue is root mass versus leaf mass. The new rootmass, regardless of how big it is, is not ready to handle supporting a large leaf surface (water loss through evaporation). You solve this imbalance by decreasing evaporation, since only time, and more roots will increase water intake. Increasing humidity or decreasing leaf surface both decrease moisture loss. More shade and less sun also helps decrease evaporation. If you have sufficient humidity, evaporation will essentially go to zero. Patience is a virtue,
With my air-layers early this summer, they went to a humid greenhouse for a week, or so, and then to mostly shade with a little filtered light for 3-4 weeks. After 5-6 weeks, the roots were coming out of the drain holes of a gallon pot.