Are you dragging the videos on existing composition?
Delete all compositions in project panel.
Then drag the footage into timeline, the composition will automatically take the dimensions of footage.
Alternatively, select the clip and press ctrl+alt+F. it will snap the footage to the composition dimension.
Hope it helps.
Did the steps work for you?
If yes, then please confirm so that people getting similar issues also get to know.
yes they did.......... I don't know how to confirm...... do I just say confirmed?
you just confirmed it.