I'm in the boat as you. Mine (jacaaanda mimosa & a jacaranda) approximately 1 year old. Both lost some leaves and limbs this summer here in Mohave county. I thought maybe too hot and/or too much water. Now i cut water back but still both have dry brownish brittle on ends of foilage. Idon'tthink your tree is dying if it's getting some new buds. However I'm also stumped as to why the dryness brown leaves. Maybe someone can help?