yeah the single perimeter is for testing.

make some 2mm tall cubes and see if you get the same result.

Also - is that the idex printer ? (yes it is)

is it printing with just the one extruder ?

If not check the individual extruder offsets.

But basically run a bunch of small test shapes and see if you get the same results - and if not, check the cad, model carefully - could simply be something in the actual model that's slipped past you :-)