I have a problem while exporting and importing vertex groups data through OBJ format. I have certain vertex groups in my object which consist of only single vertex (as shown in the following two images)
Now I export it by checking the 'polygroups' option and the 'keep vertex order'option in the OBJ export options and then import it by checking the 'Polygroups' option under 'Keep Vertex Order' tab in the OBJ import options. I see that, as expected, the vertex order is maintained, but when I tried selecting the vertex groups, I am selecting faces (as shown in the following images). How can I prevent this from happening? Why is the vertex group with single vertex changing into a vertex group with 4 vertices and the corresponding face is getting selected when the vertex group is selected?