Q.fig tree
My turkey brown fig tree is about 6 years old. It was growing well with good fruit production. This year, after the tree started growing new leaves, half the tree suddenly started losing all its leaves. They were green, looked kind of wet/frozen look. Five weeks later, still no new leaves are growing, the tips are green and have new leaf buds, but they fall off. The other half of the tree is growing good with baby figs. The tree has two main trunks from the ground, one half is just fine and the other one appears to be dying. I do see some webs on the side that is not doing well, which I have treated with Neem oil, but it has not helped! I live in zone 9. Please help!
This sounds very much like Leaf Blight. The dead leaves are often held together with fine threads, much like you describe. The only thing to do is make sure you are removing any disease leaves and dispose of them.
https://www.gardeningknowhow.com/edible/fruits/figs/common-fig-tree-diseases.htm
http://extension.uga.edu/publications/detail.html?number=C945