Material assigned to OBJ mesh doesn't display in the running project

[Favkis]

Godot version:
v3.1.stable.official

OS/device including version:
Windows 10

Issue description:
Imported model has textures in editor, but when I press F5 (in-game) it appears white, like without textures.

Steps to reproduce:
Not sure, imported obj file, then double clicked, tried to change materials, looked like they were saved, so I placed model to main game scene, in editor there are textures, but once I started game, there was none.

There were 2 materials expected from that .obj model, cause it had UVs and 2 materials inside
Here is screenshot of texture being in editor, but not in game

And here's how I "fixed" the issue

[KoBeWi]

Still valid in 3.2.4 beta3