Firstly, I am unsure if this is a bug, or the new intended behavior of this.
Previously, you could take a part, any type; Part, Wedge, etc… or union and export it via “Export Selection”. This would save the .obj and .mtl files for the object respectively. Now the .mtl never worked, but now when exporting the Part/Union, whatever it may be, doesn’t actually export a proper object file. You can’t insert it into Blender, and when trying to insert it back into studio, it gives you a script;
Now this script is unique to each different object as expected.
No beta options are enabled.