OBJs no longer separating into separate meshes based on materials (2018)

This is probably has a short and obvious solution, but after swapping from 2017 and using the Asset store version to 2018 and using the Package Manager version, I can no longer separate the mesh into parts based on material while exporting as an OBJ. Is there a setting that I am missing in order to allow for this?

Also, brand new to (any) forums, so my apologies if I asked without syntax or failed to find if this was previously brought up.

If I remember correctly, I changed the OBJ exporter to instead write Unity submeshes into material sections instead of separate groups. The results should be the same when importing to other DCCs or Unity, however. Is something not working as you’d expect (other than the differing OBJ format)?

I had previously been using the different segments of material meshes for certain collisions, but if it no longer does that I’ll just duplicate the mesh and break it apart by materials, exporting them individually. Unless I’m massively misunderstanding something.

The exported OBJ should import to Unity with separate sub-meshes for each material. I just checked with the latest preview build (at time of writing. 4.3.0-preview.2), it is working as intended. How are you applying materials to the ProBuilder mesh?