Umami Burger: Where did “U” go?

Oh the simple days when the “U” branding of Umami Burger took over Instagram by storm. It was all that I was seeing at a certain point in 2015. But then suddenly, they vanished - like the Avatar. Although I don't know if the world necessarily needed Umami Burger like Aang but few would beg to differ. It just got me wondering what happened with the chain and where are they now?