An export always reflects what is on the sequence. Perhaps there was extraneous content at the head that was overlooked before exporting??
It appears that audio and video for the clip are not linked, and that this was simply an audio track intended to match up to existing video.
After importing the audio, split off and delete the silence at the beginning if necessary. Then drag the audio track to where it should be.
To drag ALL clips simultaneously click the first clip, hold down <shift> and click the last, to select them all. Then drag.
Or select all clips that are to be moved, right-click on one of them and GROUP CLIPS. Drag.