Using Altium 18.1.7:

If I do a New/PCB, File/Import/Gerber File (file.GTS). I get an image with some of the SMT pads shown only as just dots.
If I just do a File/Open on the same Gerber File the image looks normal with all pads present.

I need to load the file in the PCB mode so Export DXF is available.

Any ideas on why one method looks OK yet the other has missing pads?