I got this large tree at Costco about a month ago. It’s in Southern California near and east facing window. I water it about once a week with about 2-3 cups of water a week. It just dropped its first leaf and it’s relatively large. It had a lot of brown going down the spine starting at the top. I’m not sure if I’m over watering or under watering. I included some pictures of other brown spots on the leaves still on the tree.