when importing video, it doe not scale to 100%

When I pull the Video (3840 x 2160) into the Projekt Folder, I can see 100%. If I drag it into the Timeline, it does not show the whole Picture, so I have to scale it down to 60% to view the whole Image but then I see the black borders. Videosettings in premiere are also 3840 x 2160. Also if I click onto the Scene and match it with the framesize, nothing happens. Had this Problem for just 1 day. Otherwise it works perfectly. Can someone help ?