ArcGIS has multiple 3D style sets that allow the placement of 3D point symbology such as the 3D Street Furniture style depicted below. We have built our own style set from the available ESRI data and incorporated them into our GIS.

Recently I have attempted to extend our 3D symbology to include custom symbology using 3D shapes, with no success. We created new 3D shapes using COLLADA (.dae), OpenFlight (.flt), and Wavefront (.obj) models. We also downloaded a few simple 3ds Max (.3ds) files for testing, we do not currently have access to 3DS Max. The shapes render great in their respective apps but nothing is displayed when importing the files into ArcGIS Pro as a 3D model mark and no error messages.

What is the proper workflow and software to create a custom 3D model mark for use in ArcGIS Pro?