I played around with Google Earth online and noticed two things:
It is based on Google Earth Desktop, and unfortunately on a buggy version which has a broken COLLADA (3d model) reader that causes models to be imported oversized and most of the time sheared (I believe this is only noticeable when there are nested groups).
It does not display textures on COLLADA models.
As far as I remember there was no workaround for this bug. If you have groups or components, maybe try exploding all? If it’s not skewed but just at wrong scale, maybe figure out the scale factor?
Otherwise if it is very simple geometry (extruded polygon) you could export not as 3D model (built-in kmz exporter) but as geometric primitives using a very old extension that may work or may not work anymore. Maybe there exist alternative export workflows (e.g. SketchUp → CityGML (?) → plain KML without models).