Archicad only supports 3 CAD formats per their online documentation. The file formats are .DXF, .DWG and .DGN. This is a limitation of Archicad. Shapr3D clearly states that it exports files in STP and IGS that is support by MOST major CAD vendors.
As to the support for AutoCAD, I have used Shapr3D exported STP files with AutoCAD Mechanical. AutoCAD 2017 doesn't appear to support STP or IGS files. Many other AutoDesk products do such as Fusion 360 and Inventor in which I have used both and currently use Fusion 360.
Which version of AutoCAD are you using?