I planted two red maple trees in April and in July. The leaves began turning brown at the tips until all the leaves fell and in late September they budded out again until the winter came, then the leaves fell again.
Maples Budded Out Again in Fall
Certified GKH Gardening Expert
The trees likely dropped their leaves due to stress of planting. They will drop leaves to save energy for the roots.
The fact that new leaves grew tells you the plant has become established and is growing.
Continue to care for the trees. The link below will refresh you on the care requirements.