Can't find navigation segment (Warframe)

In the mission to find the Navigation Segment during the tutorial, when Ascaris goes into combat mode, I can't find this thing. I watched the video and I know how it looks, but at this place I just have a hole in the floor, and there is no stand for the segment. I tried to restart the mission, tried to restart the game and the mission - 3-4 times exactly nifiga does not change. Just a hole in the floor and that's it. Help me please