Basically, if you delete something from the middle of the track, all of the items which are placed on the right side are going to automatically move to the left in order to fill in the gap.
However, if you disabled the Auto Ripple Edit, then Filmora9 works the other way around. So if there is blank space left in the timeline after you cut/delete the video, you can toggle it on by clicking on its icon that is located next to the Manage Tracks icon in the upper left corner of the timeline, see below.
