Hi there, 

when exporting selected pattern pieces and leave the buttons unchecked, randomly they will be exported with the selected pattern pieces. When I check in Blender, the exported mesh will have the buttons, that i unchecked in the Export obj window...

please see screenshot below. 
What´s also funny is, that (also randomly), when i export the buttons separately, the texture gets lost. Meaning, when I check in Blender, the buttons come without texture. This seems not only to be a bug in CLO 3D, but also in MD. 
Where do you store the information, where the buttons are attached to the mesh (in the xml, there are only the seamline pairs stored)?

Please let me know your feedback, 
all the best, 
helavonasgard