All of them were planted in the spring. At this stage, just continue to water. Hydrangeas don't do well in the sun, and they require water at all times. Transplanting can also be a shock to their system. Keep them alive, and by next spring they should be acclimated to the move.
Many plants are struggling with our dry, hot weather, so continue to water.
Monitor the plants next spring, and if you see spots again, call your county extension office for a fungicide recommendation. My son and his wife gave me a beautiful blooming hydrangea for Mother s Day. After it quit blooming, I planted it in my flower bed. It did great until now. I sprayed it a few days ago with a pyrethrin, along with my azaleas.