Since the new version of Twinmotion we have noticed that importing models in *.obj format works without any problems, even the hierarchy levels are displayed, but when you put a texture on it, the whole model is covered with this texture and not the individual elements.
I can send them the model with pleasure, that they can have a closer look at it.
Thank you for posting your issue in the community and there seems to be a bug related to the display of textures. Here are things you can try to restore the texture.
Navigate to the Preferences > Quality settings and change it to something different such as Medium and then the texture should refresh. Then you can revert the setting back.
Closing and reopening the file could restore the texture as well.
If that did not help please report a bug by following this link so we can further investigate this issue: