Same issue here. The material does not update in my render or material preview render if I change something like base colour of the material.
However, if I change a parameter like the pattern type of a floor material, the base colour updates correctly in the render.
Also, I don't know if this is part of the same issue, but sometimes when making changes to the substance material, the interactive render stops and does not update until I restart it - that makes it more time consuming to make small changes.
Has nobody looked into this?