Last year fig tree had leaves with brown dry margins. Wintered over outside in large container. Started spraying with copper just when you could see growth. Now leaves started to fully appear and looked fine but today some have started brown at margins. What is this?

Probably Fig Rust, its a fungus. When you have it once, then you will keep getting it because of the spores lie dormant waiting for the right conditions. . This process can happen very quickly, in just a few weeks. Leaf-drop can take place any time after fig rust strikes, often each year around the same time. The best way to have a healthy fig tree is find another location with better conditions.