I've been checking your scene and I'm afraid that there isn't an easy solution to use the random texture with your instances. The problem is that the number of instances is not the same in all the frames, so after reloading the instancer for each frame, the IDs used to get the random texture change. Perhaps you could use a texture in world space to add the random appearance or something like that, but not the random texture node.
Computer Graphics Software Developer
Octane plugin development and support: LightWave and Houdini