The girls were at the festival on the 9th, performing "Red Light", as well as Amber's "Shake That Brass". The girls took over the London crowd with their command of the stage even without Sulli.
As of the 7th, Sulli had left f(x) to go on her own way as an actress. SM Entertainment had said that the girls will be juggling group and individual activities just as they have done before. Sulli will also be working with the agency to decide on her future projects.