Well, that’s odd. I’m not sure I ever noticed that metric units weren’t selectable options on my Mac.
But do you have units set to Millimeters, Centimeters, or Meters?
I think the issue is that while you might be working in one set of units, the CAD file could have been done in a different set of units. We see this all the time where imports are the wrong size because of the units mismatch. When the user sets the units to match the original file units, the problem goes away.
Not if it is imported with the correct units. If it was imported at meters, though, it’s a little bit different.
Here’s the file. I imported with units set to millimeters but I have the model units set to meters.
Simons Garden.skp (1.1 MB)