OBJ Transparency Not Working

[KoStard]

Describe the bug
I create OBJ files in python with d 0.05 for my material. When I create the obj and open in Online3DViewer, in the materials section it shows that the opacity is 5%, but the material doesn't have any transparency. See the screenshots and the attached test file.

To Reproduce

1. Open https://3dviewer.net/index.html
2. Drop the test.obj file attached in the issue

Expected behavior
Opacity should have clear visual effect.

Screenshots

Same file in https://www.creators3d.com/online-viewer

[KoStard]

Zipped the obj file due to GitHub limitation on attached file formats:
test.zip