The drawings made in AutoCAD are probably may have been made very far from the origin point.
Select
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all your drawings by pressing Ctrl + A on the keyboard while in perspective screen.
Enter the Move command.
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Click on a point of your drawing in the plan window to set the reference point.
Press the X key on the keyboard. The cursor will go to the X box in the coordinate box. Type the value 0 and press Enter. The number will be covered in red.
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Press the Y key on the keyboard. The cursor will go to the Y box in the coordinate box. Type the value 0 and press Enter. The number will be covered in red.
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When you click the left mouse button, your drawing will be moved to the origin (0,0) point relative to the reference point.
Press the Home key on the keyboard .
The perspective camera (the image in its window) will come to the starting position of the program (the angle visible from the origin point).