The white scale line is an indicator of distance relating to viewed graphics area. If you change the viewing area you will see that scale change. The lower left bottom hole
is located the same distance from o,o in your drawing even the diameters are different.
On import LC uses the same location for the starting point, namely 0,0 if set as the default / as drawn checked, but, if you are fooling around with the available tools, such as Tools>Scale Drawing LC will change the
0,0 location of the drawing to the extents of the any drawn objects.
You can avoid any of this happening if you just create layers of the machining task you are going to be doing as suggested and highly recomended in the manual.
RICH