Here is the way to reproduce the bug:
- Sync a 3dsmax scene into Twinmotion
- Apply materials in Twinmotion
- Isolate some objects in 3dsmax (or hide objects / layers)
- Resync the scene in Twinmotion
- Turn off isolate in 3dsmax
- Resync scene
- Some materials will reset and forget the materials applied in twinmotion