By default SU 2015 behaves this way in a new model file:
Click… Model Info > Geo-location > Set Manual Location
The Set Manual Geo-location dialog appears and it is prefilled with the default location.
40.018309N 105.242139W (SU Home Office, Boulder Colorado)
Notice if you click OK in the Set Manual Geo-location dialog, nothing happens.
That is, the Model Info-Geo-location panel still states…”This model is not geo-located”
Now make a change to either or both of the L - Lo settings in the Set Manual Geo-location dialog.
Then click OK in the Set Manual Geo-location dialog.
The Model Info-Geo-location panel then states…”This model is manually geo-located”
I have no ‘official’ knowledge of why it works that way.
Perhaps it’s to keep inexperienced users from inadvertently geo-locating their model.
After you import the KMZ, go to the Set Manual Geo-location dialog.
Make a notable change to one of the L,Lo values. Say, change the L by 10°
Then click OK … Model Info then says the model is geo-located.
Then go back to the Set Manual Location dialog and change the L to the previous (correct) value.