Opacity not working in Mantra

[perpen]

Hi,
The output opacity from Designer works well in my Houdin viewport, but it doesn't work rendering with Mantra. It appears there is no connection to opacity in the SubstanceToPrincipled.cfg so I added this:
      "opacity": {
        "opaccolor_texture": "%map%",
        "opaccolor_useTexture": "1",
      }

But still no luck. I am on Ubuntu, Houdini 17.5 and latest version of Designer.
Thanks!

[perpen]

I change to SubstanceToMantra_Experimental.cfg and it's working properly.