i checked once again, i have the timeline selected and then when i play i can see a full size clip playing in the Canvas, it is the clip that is selected in the multiclip in the Viewer. But the clips in the Viewer doesnt play. When i pause the timeline the pictures in the viewer is updated to the current position.
So instead that the Multiclip is playing all four clips simultaneously it shows only still pictures of the point where i have paused the timeline.