This is probably because the family has 2D geometry that is visible only in plan view, and probably, this 2D geometry is not correctly dimensioned.
As Rodrigo said, you will have to edit the family, identify the 2D geometry and correct it.
The geometry you have to correct is probably 2D "symbolic lines": "symbolic lines" in the family environment are the equivalent of "detail lines" in the project environment, they only display in the view they are created in.
The "visibility settings" of the 3D geometry of that family are set so that they do not display in "plan" views, (and maybe the "front/back" and "left/right" views), letting only the 2D "symbolic lines" represent the element.
Normally, you have to "lock" the symbolic lines to the "reference planes" that drive the 3D geometry in order to have all the representations matching the dimensional changes of the family.
However, quiet often, poor quality content, instead of using "native" 2D "symbolic lines" use AutoCAD blocks imported as 2D geometry in the family. AutoCAD geometry is not flexible, so changes in the 3D geometry cannot be reflected in the 2D geometry of the imported AutoCAD block. If this is the case you will probably have to re-create the 2D geometry of the family per view using "symbolic lines".
hope it helps
Aghis
