Mark Elendt

In the daily build of H20.5, you should see a recipe (Karma Texture Controls) on the Mtlx Image node that adds the karma specific properties to the node.

This is probably a lot easier than using the edit properties node.

Please submit a bug.

Redicing production scenes can be quite expensive so Karma turns off IPR continuous dicing by default. The dicing is "locked off" the first render, and reused. If you turn on IPR Continous Dicing, karma will redice the scene as the camera moves (or you tumble around).
Is this what you're experiencing?