Painted Trees Not Displaying Leaves

Hi, Please can someone assist me with this issue:

I have imported tree assets from TreeIt into unity. There are 2 materials one for Bark and one for Leaves and a model for the tree.I have also set the shaders to the correct nature shaders - Nature leaves/Nature Bark. Dragging and dropping the tree asset into the scene works perfectly and materials look great but when I load the tree into the terrain painter the trees show no leaves :frowning:

See screenshot below (trees on left dragged individually and trees on the right are painted with terrain tool)

Please, anyone can help?