Sounds like shock to me. What you need is a rooting hormone and something for shock namely Vitamin B1. There are other hormones and additives that can be had through a nursery. Another thing to consider is that you are going from pure water to soil. you may need to soak the soil to soaking wetness right after planting. Keep the plant is shade for a little while until it adjusts to the new area. when I transplant herbs and some vegetables started indoors I hang a bit of shade cloth over the area reducing the amount of direct sunlight for a period of two weeks. Shade cloth is more of a net or a screen, it allows some direct some light, diffused so it is not over powering. If planting out doors into the soil you may want to reduce the amount of heat getting to the soil. You can either use 3-4 inches of mulch material like stray (hay has seeds a big no no to use) or grass clippings. Or you can lay sheets of tin foil around the plant, in triangular fashion leaving a small hole in center for the plant. In the case of organic mulches you would want to pull the mulch from the base of the plant to half way to the drip line - the edge of the leafy part so its own shade will still protect its own roots.