Importing OBJ is creating seams at materials borders

Brand new to Nomad, and my searches haven’t provided answers I need. So I am importing a base daz model obj, which needs to keep its vertex order, count, and groups. I believe I found the option to make that work, except for vertex groups are gone once brought back to blender. But my main issue that I need to solve first is, its breaking up the mesh into its materials which means when I export, it no longer works correctly in any of my other apps. Is there a way to stop this from occurring?
Here is what it looks like after export, having done nothing but import into nomad, then exporting. Those edges should not be there, and it means I can’t bring it back to daz as the topology doesn’t match.