@Torsten_K I am also seeing this with some of our users. One in particular, sharing Excel, the user viewing the shared windows (2) sees no flicking, user sharing (1) does. However, if 2 then requests control and it is granted, the flickering stops on 1's screen. We do not see this as a widespread issue though and I'm struggling to see a resolution. Windows is up to date, no driver issues I can see. We think this was fine before the last windows update dropped.